diabetes mellitus in south asia: scientific evaluation of the research output...

ORIGINAL ARTICLE

Diabetes mellitus in South Asia: Scientific evaluationof the research outputPriyanga RANASINGHE,1 Ranil JAYAWARDENA2,3 and Prasad KATULANDA2

1Department of Pharmacology, Faculty of Medicine, University of Colombo Sri Lanka, 2Diabetes Research Unit, Department of Clinical

Medicine, Faculty of Medicine, University of Colombo Sri Lanka and 3Institute of Health and Biomedical Innovation, School of Human

Movement Studies, Queensland University of Technology Brisbane, Queensland, Australia

Correspondence

Priyanga Ranasinghe, Department of

Pharmacology, Faculty of Medicine,

University of Colombo, No. 25 Kynsey Road,

Colombo 08, Sri Lanka.

Tel: +94 714 039413

Fax: +94 112 596368

Email: [email protected]

Received 27 December 2011; revised 23 July

2012; accepted 19 August 2012.

doi: 10.1111/1753-0407.12003

Abstract

Background: Diabetes in South Asia represents a different disease entity in

terms of its onset, progression, and complications. In the present study, we

systematically analyzed the medical research output on diabetes in South

Asia.

Methods: The online SciVerse Scopus database was searched using the search

terms “diabetes” and “diabetes mellitus” in the article Title, Abstract or Key-

words fields, in conjunction with the names of each regional country in the

Author Affiliation field.

Results: In total, 8478 research articles were identified. Most were from

India (85.1%) and Pakistan (9.6%) and the contribution to the global dia-

betes research output was 2.1%. Publications from South Asia increased

markedly after 2007, with 58.7% of papers published between 2000 and

2010 being published after 2007. Most papers were Research Articles

(75.9%) and Reviews (12.9%), with only 90 (1.1%) clinical trials. Publica-

tions predominantly appeared in local national journals. Indian authors and

institutions had the most number of articles and the highest h-index. There

were 136 (1.6%) intraregional collaborative studies. Only 39 articles

(0.46%) had >100 citations.

Conclusions: Regional research output on diabetes mellitus is unsatisfactory,

with only a minimal contribution to global diabetes research. Publications

are not highly cited and only a few randomized controlled trials have been

performed. In the coming decades, scientists in the region must collaborate

and focus on practical and culturally acceptable interventional studies on

diabetes mellitus.

Keywords: analysis, diabetes mellitus, medical research, publication, South

Asia.

Significant findings of the study: The contribution of South Asian studies to global research output on diabetes

mellitus during the past decade is 2.1%. The number of randomized controlled trials from the region accounts

for only 1.1% of total research publications.

What this study adds: There is an urgent need for scientists in the region to collaborate and focus on practical

and culturally acceptable studies on diabetes in coming decades.

© 2012 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd34

Journal of Diabetes 5 (2013) 34–42

ASIA

TRACK

Introduction

South Asia, commonly known as the Indian sub-

continent is comprised of seven countries: Bangladesh,

Bhutan, India, Maldives, Nepal, Pakistan, and Sri

Lanka. The land surface area of the entire region is only

approximately 10% of the Asian continent and 2.4% of

the world.1 However, South Asia accounts for approxi-

mately 25% of the world’s population, making it the

most densely populated geographical region worldwide.2

It is home to a vast array of peoples from many diverse

ethnic, cultural, linguistic, and religious backgrounds.3

Despite this diversity, regional countries face many

common health challenges.4 Most South Asian countries

bear the triple burden of infectious diseases, non-com-

municable diseases, and injuries.5 In addition, health

systems have to deal with a lack of local evidence-based

policies and/or guidelines, limited social accountability,

and inequities in the provision of limited resources.4

Research is an essential guide to improving health

systems and developing new initiatives.6 Although

investment in infrastructure for health research is stea-

dily increasing, gaps remain in regional evidence to

guide reductions in important regional health problems,

such as non-communicable diseases.7

Diabetes mellitus has reached epidemic proportions

worldwide, with its prevalence rising globally, particu-

larly in developing South Asian countries.8 An estimate

for 2011 reported that 8.3% of the South Asian adult

population has diabetes, a figure that is expected to

reach 10.2% in 2030.9 According to the International

Diabetes Federation (IDF), Southeast Asia had the sec-

ond highest number of deaths related to diabetes in

2011.9 India has the second highest number of patients

with known diabetes worldwide, with one in three

Indians between 50 and 59 years of age and one in four

urban Indians over >20 years of age having impaired

glucose tolerance (IGT) or diabetes.9,10 Other regional

countries report similar epidemic levels.11–13 South

Asians are known to have an increased predisposition to

Type 2 diabetes compared with other ethnic groups.14

In addition, diabetes tends to occur at a much younger

age and progress more rapidly than in other ethnici-

ties.15,16 Cardiovascular complications of diabetes are

more common among South Asians, with a 50% higher

mortality compared with Europids.17 Similarly, renal

disease is also threefold more common among South

Asians than Europids.18 It is evident that diabetes

among South Asians represents a significant health con-

cern with differential etiopathogenesis than among other

ethnicities. In addition, the rapid expansion of the popu-

lation in most South Asian countries has led to a major-

ity of people living below the poverty line. Therefore,

diabetes mellitus has placed an added burden on the

already economically strained South Asian countries,

patients, and their families.

Diabetes among South Asians represents a disease

entity with differential etiopathogenesis. Diabetes is

associated with a host of life-threatening and potentially

disabling complications, which are more prevalent

among South Asians. Hence, in addition to the direct

excess healthcare expenditure due to the rapidly increas-

ing prevalence of diabetes, there is also a much larger

burden in the form of lost productivity as a result of

restricted daily activity and reduced work efficiency.

Regional research is one of the most important corner-

stones in tackling this common and important health

challenge. At present no studies have comprehensively

evaluated the regional research output on diabetes.

Thus, the aim of the present study was to systematically

analyze the medical research output on diabetes mellitus

from the South Asian region. The study focused on eval-

uating the evolution of South Asian medical research

output on diabetes, examining the research productivity

and impact of leading regional institutions, identifying

patterns of regional and international collaboration, as

well as the authors from each regional country, and

comparing the regional research output on diabetes with

that of other regions and the rest of the world.

Methods

Diabetes research output for the South Asian region

was determined as follows. First, a search was under-

taken of the online SciVerse Scopus database (Elsevier

Properties SA; http://www.scopus.com, accessed 21

November 2011) using the search terms “diabetes” and

“diabetes mellitus” in the article Title, Abstract, or Key-

words fields. These terms were used in conjunction with

the names of each regional country (Bangladesh, Bhu-

tan, India, Pakistan, Maldives, Nepal and Sri Lanka) in

the Author Affiliation field. The search limits consisted

of date range (“all years” to “present” [21 November

2011]), subject areas (Life Sciences and Health Sciences),

and document type (Article, Review, Letter, Editorial,

or Short Survey). Conference papers, errata, conference

reviews, and articles in press were excluded from the

study. Second, all the papers identified using the original

Scopus search with the inclusion and exclusion criteria

were screened by reading the Title and Abstract and

studies not satisfying the search criteria were excluded.

The studies selected for inclusion at this stage were fur-

ther screened for suitability by reading the papers. This

was done independently by two authors (P.R. and R.J.),

with the final group of articles to be included in the

study determined after an iterative consensus process.

© 2012 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd 35

P. RANASINGHE et al. Diabetes research in South Asia

ASIA

TRACK

The most recent diabetes prevalence data for regional

countries were obtained from the IDF Diabetes Atlas.9

This was used to standardize the number of publications

on diabetes from each country per million patients with

diabetes in the respective countries for comparative pur-

poses. The total number of Scopus-indexed medical

publications for each regional country was determined

by restricting the search with the name of the country in

the Affiliation field. This was then compared with the

number of diabetes-related publications from regional

countries. To evaluate the impact of regional publica-

tions on diabetes, the h-index of the authors and

institutions was calculated using the Scopus h-index

calculator. The h-index is an index that attempts to mea-

sure the impact of the published work.19 The publica-

tions were also grouped according to the most prolific

authors and institutions from each regional country,

and the number of regional and worldwide collabora-

tions was also evaluated. The top 10 journals with the

highest number of publications on diabetes mellitus

from the South Asian region and the rest of the world

were identified and were ranked based on the source

normalized impact per paper (SNIP) factor. The SNIP

measures contextual citation impact by weighting cita-

tions based on the total number of citations in a given

subject field.20 The publication characteristics of highly

cited papers (>100 citations) on diabetes mellitus from

the South Asian region were also evaluated.

Results

In total, 8478 articles have been published from the

South Asian region on diabetes mellitus. Most of the

articles were from India (85.13%), followed by Pakistan

(9.64%), Bangladesh (2.50%), Sri Lanka (1.57%),

Nepal (1.15%) and Maldives (0.01%; Table 1). There

were no articles on diabetes mellitus from Bhutan. How-

ever, when standardized against the number of patients

with diabetes, Nepal had the highest number of articles

on diabetes mellitus (Table 1). Similar numbers were

found in India, Sri Lanka, and Pakistan, but the lowest

was found in Bangladesh (Table 1). The total number of

publications on diabetes mellitus worldwide (from year

1828) was 396 325, with the highest number of publica-

tions being from the US (24.8%). The South Asian

contribution to the global research output on diabetes

was 2.1%, with the first publication being from India in

1958 (Table 1). The percentage contribution from the

South Asian region to the global research output on

diabetes has increased over the years from 0.02% in

1951–1960, to 0.08% in 1961–1970, 1.49% in 1971–1980, 0.95% in 1981–1990, 1.36% in 1991–2000, and

2.81% in 2001–2010.The total number of publications related to medicine

from the South Asian region was 414 344, with most

being from India (Table 1). A comparison between the

number of articles on diabetes and the total number of

medical publications for each country and the South

Asian region is presented in Table 1. Two percent of all

medical research publications from the South Asian

region were on diabetes mellitus, with only a slight vari-

ation among regional countries (Table 1). The number

of publications on diabetes has increased steadily over

the decades in all regional countries, with India showing

the most prolific increase (Table 2). A timeline trend for

South Asian and worldwide publications on diabetes

during in the past decade (2000–2010) is shown in

Fig. 1. The percentage of publications was calculated as

the number of publications for a particular year/total

publications on diabetes for the decade 2000–2010.Worldwide, the number of publications related to diabe-

tes has also increased steadily from 2000 to 2010

Table 1 Diabetes mellitus publications according to country in the South Asian region

Country Period of publication

No. diabetes

patients* (9106)

No. publications

Medicine Diabetes mellitus† (%) Per million patients

India 1958–2011 61.26 366 097 7217 (2.0) 117.8

Pakistan 1964–2011 6.35 27 279 817 (3.0) 128.7

Bangladesh 1976–2011 8.41 10 279 212 (2.1) 25.2

Sri Lanka 1973–2011 1.08 5672 133 (2.3) 123.2

Nepal 1998–2011 0.49 4785 98 (2.0) 200.7

Maldives 2006 0.02 56 1 (1.8) 65.8

Bhutan N/A 0.02 176 0 (0) 0

South Asia 1958–2011 77.62 414 344 8478 (2.0) 109.2

*The number of diabetes patients was obtained from the International Diabetes Federation World Diabetes Atlas.9

†The values given in parentheses show the number of articles on diabetes mellitus as a percentage of the total number of articles published in

the field of medicine.


Diabetes research in South Asia P. RANASINGHE et al.

ASIA

TRACK

(Fig. 1). In the South Asian region, the number of publi-

cations on diabetes mellitus has increased markedly

from 2007 onwards, with 58.7% of articles published

between 2000 and 2010 having been published after

2007 and nearly one-fifth of all articles published in the

past decade from the region being published in 2010

(Fig. 1).

Most of the articles from South Asia have been

Research Articles (n = 6437; 75.9%) and Reviews

(n = 1096; 12.9%), followed by Letters to the Editor

(n = 528; 6.2%), Editorials (n = 204; 2.4%), Short Sur-

veys (n = 115; 1.4%) and Notes (n = 98; 1.2%). There

were 5365 studies based on humans (63.3%) and 2349

performed in animals (27.7%). Most of the human stud-

ies were on type 2 diabetes mellitus (85.1%), with only

14.9% on type 1 diabetes. Only 90 clinical trials on dia-

betes have been published from the South Asian region

(1.1% of regional publications on diabetes), compared

with 36 964 clinical trials (9.3% of global publications

on diabetes) from around the world. Prevalence was

investigated in 928 (10.9%) publications, whereas 1847

(21.8%) studies evaluated risk factors and 347 (4.1%)

studies evaluated pathophysiology. There were 381

(4.5%) and 884 (10.4%; retinopathy n = 326; nephropa-

thy n = 319; neuropathy n = 239) studies on macrovas-

cular and microvascular complications of diabetes,

respectively.

The top 10 journals in which the maximum recent

worldwide or South Asian publications on diabetes

mellitus appeared are listed in Table 3. South Asian

publications predominantly appeared in national jour-

nals from India and Pakistan. Only one international

journal in the list of top 10 journals worldwide (Diabetes

Research and Clinical Practice) published multiple arti-

cles from South Asian countries. The journals with the

highest publications from South Asia had a very low

SNIP, with most having a SNIP <1.0. In contrast, seven

journals from the Diabetes and Endocrinology field and

three from the General Medicine field published the

maximum number of diabetes publications worldwide

Table 2 Number of diabetes mellitus publications according to country in different decades

Country

No. of publications

1951–1960 1961–1970 1971–1980 1981–1990 1991–2000 2001–2010

India 1 9 471 445 896 4587

Pakistan 0 2 12 14 80 624

Bangladesh 0 0 4 9 41 139

Sri Lanka 0 0 5 4 23 88

Nepal 0 0 0 0 4 86

Maldives 0 0 0 0 0 1

South Asia 1 11 492 472 1044 5525

World 6111 14 621 32 856 49 463 76 303 196 709

Year

% r

egio

nal/t

otal

DM

pub

licat

ions

% D

M p

ublic

atio

ns w

orld

wid

e/to

tal p

ublic

atio

nsFigure 1 The number of diabetes mellitus (DM) publications from the South Asian region as a percentage of all DM publications from the region

between 2000 and 2010 (■) and the number of DM publications worldwide as a percentage of all publications (●) between 2000 and 2010.



ASIA

TRACK

(Table 3). Almost all journals in the worldwide publica-

tions category had high SNIPs, indicating a higher

impact of publication. The percentage of publications

from the South Asian region appearing in the top 10

journals with highest number of publications on diabe-

tes worldwide was minimal (Table 3). The number of

articles in regional journals (i.e. published by South

Asian countries) was 4008 (47.3%), with most publica-

tions appearing in international journals (n = 4470;

52.7%). The number of citations per paper was signifi-

cantly higher in articles published in international com-

pared with regional journals (7.9 vs 2.5, respectively).

The top three authors and institutions with the most

number of publications on diabetes mellitus from each

regional country are given in Table 4. Indian authors

and institutions had the highest number of articles and

the highest h-index (Table 4). In most other South Asian

countries, the number of publications by individual

authors and institutions were relatively lower and these

publications also had lower h-indices. When evaluating

worldwide publications on diabetes, authors with

the most number of publications had a higher h-index:

for example, J. Tuomilehto (h = 77), H.H. Parving

(h = 73), and A.J. Scheen (h = 41). The total number of

collaborative studies among regional countries was 136

Table 3 The top 10 journals with the most number of publications

on diabetes mellitus

Worldwide South Asian region

1. Diabetes Care (0.67%)

n = 11 282; SNIP = 3.624

1. Journal of the Association

of Physicians of India

n = 348; SNIP = 0.329

2. Diabetes (0.27%)

n = 8107; SNIP = 3.211

2. Journal of the Diabetic

Association of India

n = 257; SNIP = NA

3. Diabetologia (0.64%)

n = 7128; SNIP = 2.411

3. Journal of the Indian

Medical Association

n = 187; SNIP = 0.192

4. Diabetic Medicine (1.35%)

n = 4886; SNIP = 1.494

4. Diabetes Research and

Clinical Practice

n = 184; SNIP = 0.964

5. Diabetes Research and

Clinical Practice (5.13%)

n = 3584; SNIP = 0.964

5. Journal of the Pakistan

Medical Association

n = 151; SNIP = 0.358

6. Lancet (1.42%)

n = 3308; SNIP = 5.907

6. Indian Journal of Medical

Research

n = 141; SNIP = 1.059

7. Metabolism: Clinical

and Experimental (1.25%)

n = 2398; SNIP = 1.091

7. Journal of Ethnopharmacology

n = 140; SNIP = 2.515

8. Journal of Clinical

Endocrinology &

Metabolism (0.5%)

n = 2200; SNIP = 2.919)

8. Pharmacologyonline

n = 135; SNIP = 0.369)

9. British Medical

Journal (0.24%)

n = 2053; SNIP = 2.131

9. Journal of the College of

Physicians & Surgeons Pakistan

n = 125; SNIP = 0.324

10. Japanese Journal of

Clinical Medicine (0.0%)

n = 2019; SNIP = 0.044

10. Indian Journal of Physiology

and Pharmacology

n = 108; SNIP = 0.377

Values in parentheses show the percentage of publications from

South Asian countries.

n, number of publications; SNIP, source normalized impact per paper;

NA, not available.

Table 4 Authors and institutions in each country with the highest

publication rate

Top authors Top institutions

India

V. Mohan (n = 242; h = 35)

A. Ramachandran

(n = 197; h = 30)

C. Snehalatha

(n = 145; h = 28)

India

All India Institute of Medical

Sciences (n = 427; h = 36)

Postgraduate Institute of

Medical Education &

Research (n = 252; h = 19)

Madras Diabetes Research

Foundation (n = 210; h = 32)

Pakistan

A. Basit (n = 30; h = 6)

M.A. Rahman (n = 21; h = 4)

A.S. Shera (n = 18; h = 9)

Pakistan

The Aga Khan University

(n = 197; h = 17)

Jinnah Postgraduate Medical

Centre (n = 42; h = 6)

Baqai Medical University

(n = 39; h = 6)

Bangladesh

L. Ali (n = 34; h = 12)

A.K. Azad Khan (n = 20; h = 10)

H. Mahtab (n = 18; h = 7)

Bangladesh

Bangladesh Institute of

Research & Rehabilitation in

Diabetes, Endocrine &

Metabolic Disorders

(n = 67; h = 17)

University of Dhaka

(n = 50; h = 13)

Bangabandhu Sheikh

Mujib Medical University

(n = 31; h = 2)

Sri Lanka

D.J.S. Fernando (n = 22; h = 8)

P. Katulanda (n = 9; h = 3)

C.N. Wijeyaratne (n = 6; h = 2)

Sri Lanka

University of Colombo

(n = 48; h = 11)

The National Hospital of

Sri Lanka (n = 20; h = 3)

University of Sri

Jayewardanepura

(n = 19; h = 7)

Nepal

P. Karki (n = 9; h = 3)

S.K. Sharma (n = 6; h = 3)

N. Baral (n = 7; h = 3)

Nepal

B.P. Koirala Institute of

Health Sciences

(n = 15; h = 3)

Manipal Teaching

Hospital Nepal

(n = 8; h = 3)

Nepal Medical

College (n = 7; h = 2)

n, number of publications; h, h-index.



ASIA

TRACK

(1.6%). India had the most number of collaborative

studies (n = 51), followed by Pakistan (n = 29) and Ban-

gladesh (n = 23; Table 5). The countries with the most

collaborative publications on diabetes mellitus with

South Asian countries were the US (n = 426), UK

(n = 250), Canada (n = 86), Australia (n = 84), and

China (n = 63).

There were 39 articles with � 100 citations per paper

on diabetes mellitus from the South Asian region. This

is only 0.46% of the total number of publications on

diabetes from this region. The number of citations ran-

ged from 100 to 402, with most being in the range 100–200 (n = 31), followed by 200–300 citations (n = 4), 300

–400 citations (n = 3), and > 400 citations (n = 1).

Almost all the highly cited articles were from India

(n = 35; 89.7%), whereas there were only two publica-

tions each from Bangladesh and Pakistan. Thirteen of

these highly cited studies (33.3%) were collaborations

(bilateral = 11; multinational = 2), of which five were

collaborations with the UK and four were collabora-

tions with the US. Most of the highly cited publications

were animal experiments (n = 12; 30.9%), followed by

Review Articles (n = 8; 20.5%), cross-sectional studies

(n = 7; 17.9%), randomized controlled trials (n = 7;

17.9%), and cohort studies (n = 5, 12.8%). The studies

were mainly on herbal products for the treatment of dia-

betes (n = 15), risk factors for diabetes (n = 13), and the

prevalence of diabetes (n = 10). One publication each

appeared in the following three regional journals: Cur-

rent Science, Indian Journal of Pharmacology and Jour-

nal of the Association of Physicians of India. The

remaining 36 (92.3%) publications appeared in interna-

tional journals, of which most publications were in the

Journal of Ethnopharmacology (n = 11; 28.2%), Diabeto-

logia (n = 5; 12.8%), and Diabetes Care (n = 5; 12.8%).

Discussion

The present study is the first comprehensive scientific

evaluation of the South Asian research output on

diabetes mellitus. India (85.13%) and Pakistan (9.64%)

collectively contributed almost all the indexed publica-

tions on diabetes mellitus arising from this region. The

IDF reported that the total number of diabetic subjects

in India in 2011 was 61 million, a figure that is expected

increase to 101 million by the 2030.9 When considering

the numbers, it is evident that India has been impacted

by diabetes most severely, with a consequent increase in

research on diabetes explaining this country’s domi-

nance in research activities related to diabetes in the

region. India has been at the forefront of biomedical

research in the South Asian region. India is the only

country from the South Asian region ranked among the

top 20 countries based on number of publications on

biomedical engineering from 1995 to 2000.21 However,

for a meaningful comparison, it is necessary to stan-

dardize the number of publications against population

size. Our results show that there was little or no differ-

ence in the number of publications per million diabetic

patients among most regional countries. Population-

standardized publication numbers were highest in Nepal

and lowest in Bangladesh. In addition, there were no

publications indexed in Scopus on diabetes mellitus

from Bhutan. The reasons for this low number of publi-

cations compared to disease burden are multi-factorial:

at present, there is no “research culture’’ in regional

countries and among scientists; in addition, the facilities

required for research are non-existent or there is a lack

of equipment due to financial restrictions and limited

research funding.22 Furthermore, researchers from

South Asia have limited access to scientific literature due

to the high costs of gaining access to articles published

in high-impact international journals.22

Diabetes mellitus has reached epidemic proportions in

the South Asian region. According to the IDF, one-fifth

(21.9%) of the world’s diabetes population lives in

Southeast Asia.9 It is important to note that “Southeast

Asia”, as defined by the IDF, includes a wider area than

does “South Asia”.9 However, research activities related

to diabetes accounts for only approximately 2.0% of the

total medical research work performed in the South

Asian region, a figure that is relatively consistent across

regional countries. Hence, there is a clear gap between

disease burden and the research performed in South

Asia. The percentage contribution from the South Asian

region to the global research output on diabetes remains

at a very low level. It is evident from research that diabe-

tes mellitus among South Asians represents a different

disease entity in terms of its etiopathogenesis, onset,

progression, and complications.14–16,18 Each country

and region needs to be able to generate knowledge rele-

vant to their own situation to allow them to determine

their particular health problems, appraise the measures

available for dealing with these problems, and to choose

Table 5 Collaborative studies on diabetes mellitus among South

Asian countries

India Pakistan Bangladesh Sri Lanka Nepal

India – 20 14 6 11

Pakistan 20 – 4 3 2

Bangladesh 14 4 – 1 4

Sri Lanka 6 3 1 – 3

Nepal 11 2 4 3 –

Total 51 29 23 14 20

There were no collaborative studies with the Maldives.



ASIA

TRACK

the actions likely to produce the greatest improvement

in health.23 Medical research forms an important cor-

nerstone in this process. It has been shown that, in the

past, the returns on investment on health research have

been excellent, with the 25-year increase in life expec-

tancy in the US and the enormous gains in the quality of

life over the past century confirming the value to human

health of new knowledge derived from biomedical and

public health research.24 Our results also show a slight

yet promising increase in research activities related to

diabetes in the South Asian region, as evidenced by the

increasing percentage contribution to global research

output on diabetes over the decades. However, research

activities in this region are lagging far behind the rapidly

increasing regional prevalence of diabetes.

Currently, there is a mismatch between disease burden

and the technical capacity of developing countries to

make use of existing knowledge or to generate new

knowledge to combat these diseases.24 It is necessary for

developing countries to develop the research capacity

necessary to deal with their own health problems through

evidence-based decision making. In addition, <4% of

global research is devoted to diseases that dominate the

burden of disease in developing countries. Hence, it is

important for these countries to collaborate between

themselves to address common health challenges. It is

therefore necessary for countries like India, who are lead-

ers of the developing world, to play a more active role in

research into diseases like diabetes that mostly affect

them and other regional developing countries. However,

our results demonstrate that intraregional collaborations

on diabetes-related research remain at a very low level in

the South Asian region (1.6% of all studies). Hence, it is

evident that there is an urgent need to strengthen collab-

orations among the countries in this region.

Publication is a crucial part of the scientific process.

However, an equally important part is the subsequent

use and citation by others of these published articles.

Citations complete the chain of publication and are

important for the evolution of scientific knowledge.

South Asian studies on diabetes mellitus are not very

highly cited, because only 39 (0.46%) of the articles were

found to have >100 citations. This could be due to sev-

eral reasons. South Asian studies have been published

mostly in regional low-impact journals with low SNIP

scores, with the number of South Asian publications on

diabetes in international journals with high SNIPs being

minimal. Studies have demonstrated that the most

important determinant of citation is the impact factor of

the journal in which the article is published.25 Studies

have also shown the number of citations tends to

depend on the country of origin of the published work,

with citations more likely if publications originate from

institutions in developed countries, such as the US.26

This may be an another reason contributing to the lower

number of citations of articles from the South Asian

region found in the present study. The lower h-index of

published South Asian authors and institutions could

also be attributed to these factors. Furthermore, studies

from South Asia may not be cited by authors from

developed countries due to doubts regarding the nature

and quality of the publication in which they appear. The

low output of publications from South Asia in interna-

tional high-impact journals also reduces the chance for

South Asian authors to cite their own regional scholarly

works.

South Asian studies on diabetes have mainly focused

on evaluating the prevalence (10.9%), risk factors

(21.8%), and microvascular complications (10.4%) of

the condition. Only a minimal number of studies evalu-

ated pathophysiology (4.1%) and macrovascular com-

plications (4.5%). Another important finding of the

present study is the lack of randomized controlled trials

conducted into diabetes in the South Asian region, with

only 1.1% of published work based on clinical trials.

This is in contrast with a recent report that indicates that

transnational drug companies are moving their clinical

trials to India and the South Asian region due to patient

availability, low costs, and friendly drug-control sys-

tems.27 A probable reason for the lower number of clini-

cal trials identified in the present study could be that the

clinical trials conducted in South Asia are published

under affiliations from the developed country funding

the study or the company conducting the clinical trial,

hence not meeting the search criteria of the present

study. Phytotherapy for diabetes is an emerging area

with potential interest for the South Asian region, as evi-

denced by the fact that most of the highly cited papers

on diabetes were this field.

The limitations of the present study are associated

with the data source and search strategy used. The pres-

ent study used Scopus to search publications because it

has been shown to have a slight edge over other indices,

such as Web of Science and Google Scholar, for articles

related to “life sciences”.28 Scopus offers an interactive

environment for the easy tracking, storage, and classifi-

cation of research publications. However, Scopus

includes information regarding reference citations from

1995 onwards; hence, the citations for the papers may

be slightly higher than reported here. Although it does

have limitations in terms of the number of citations of a

given publication, Scopus produces the most reliable

and reproducible h-index and is therefore useful for

international and regional comparisons.29 The analysis

of the research output in the present study was

limited to studies published in English; South Asia has



ASIA

TRACK

a linguistically diverse population and some South

Asian researchers may prefer to publish their research

in native-language non-English medical journals.

Hence, the articles published in native languages are

likely to be overlooked using the present search criteria.

However, it is evident that although publications in

native-language journals contribute to local dissemina-

tion of knowledge, the regional dissemination of infor-

mation is restricted due to language barriers. Therefore,

native language articles may not have a significant

impact on tackling common regional health challenges

such as diabetes.

Conclusions

Diabetes mellitus is a considerable disease burden in the

South Asian region. However, regional medical research

output on diabetes mellitus remains unsatisfactory.

India is the major contributor to diabetes research in the

region. However, there is a slight yet promising incre-

ment in publications from most regional countries. Still,

very few articles are highly cited and there were very

results of clinical trials published in the region. It is

important that the region as a whole cooperates to con-

duct high-quality, relevant research on diabetes mellitus

and associated health issues to combat this epidemic.

Increased regional and international collaborations are

very important to enhance research capacity in regional

countries. In particular, Indian experts and research

institutes can initiate collaborative research work with

other smaller regional countries. Government policies

must be urgently focused on increasing research into

both preventive and curative studies on diabetes mell-

itus. Regional scientists must collaborate and focus on

practical and culturally acceptable studies on diabetes in

the coming decades.

Disclosure

The authors declare no conflicts of interest.

References

1. Desai PB. Cancer control efforts in the Indian subconti-

nent. Jpn J Clin Oncol. 2002; 32(Suppl.): S13–16.

2. Population Reference Bureau. World population data

sheet. 2011. Available from: http://www.prb.org/Publica

tions/Datasheets/2011/world-population-data-sheet/world

-map.aspx#/map/population (accessed 18 May 2012).

3. Ayub Q, Tyler-Smith C. Genetic variation in South Asia:

Assessing the influences of geography, language and

ethnicity for understanding history and disease risk. Brief

Funct Genomic Proteomic. 2009; 8: 395–404.

4. Sadana R, D’Souza C, Hyder AA, Chowdhury AM.

Importance of health research in South Asia. BMJ. 2004;

328: 826–30.

5. Pappas G, Akhtar T, Gergen PJ, Hadden WC, Khan

AQ. Health status of the Pakistani population: A health

profile and comparison with the United States. Am J

Public Health. 2001; 91: 93–8.

6. Commission on Health Research for Development.

Health Research: Essential Link to Equity in Develop-

ment. Oxford University Press, New York, 1990.

7. Bhutta ZA. Why has so little changed in maternal and

child health in South Asia? Br Med J. 2000; 321: 809–12.

8. Sadikot SM, Nigam A, Das S et al.; DiabetesIndia. The

burden of diabetes and impaired glucose tolerance in

India using the WHO 1999 criteria: Prevalence of Diabe-

tes in India Study (PODIS). Diabetes Res Clin Pract.

2004; 66: 301–7.

9. International Diabetes Federation. The Diabetes Atlas.

International Diabetes Federation, Brussels, 2011.

10. Ramachandran A, Snehalatha C, Kapur A et al. High

prevalence of diabetes and impaired glucose tolerance in

India: National Urban Diabetes Survey. Diabetologia.

2001; 44: 1094–101.

11. Shera AS, Jawad F, Maqsood A. Prevalence of diabetes

in Pakistan. Diabetes Res Clin Pract. 2007; 76: 219–22.

12. Katulanda P, Constantine GR, Mahesh JG et al. Preva-

lence and projections of diabetes and pre-diabetes in

adults in Sri Lanka: Sri Lanka Diabetes, Cardiovascular

Study (SLDCS). Diabet Med. 2008; 25: 1062–9.

13. Rahman MM, Rahim MA, Nahar Q. Prevalence and

risk factors of type 2 diabetes in an urbanizing rural com-

munity of Bangladesh. Bangladesh Med Res Counc Bull.

2007; 33: 48–54.

14. Mather HM, Keen H. The Southall Diabetes Survey:

Prevalence of known diabetes in Asians and Europeans.

Br Med J (Clin Res Ed). 1985; 291: 1081–4.

15. UK Prospective Diabetes Study Group. UK prospective

diabetes study XII: DIFFERENCES between asian,

afro-caribbean and white caucasian type 2 diabetic

patients at diagnosis of diabetes. Diabet Med.

1994;11:670–7.

16. Mukhopadhyay B, Forouhi NG, Fisher BM, Kesson

CM, Sattar N. A comparison of glycaemic and meta-

bolic control over time among South Asian and Euro-

pean patients with Type 2 diabetes: Results from

follow-up in a routine diabetes clinic. Diabet Med.

2006; 23: 94–8.

17. Mather HM, Chaturvedi N, Fuller JH. Mortality and

morbidity from diabetes in South Asians and Europeans:

11-year follow-up of the Southall Diabetes Survey,

London, UK. Diabet Med. 1998; 15: 53–9.

18. Burden AC, McNally PG, Feehally J, Walls J. Increased

incidence of end-stage renal failure secondary to diabetes

mellitus in Asian ethnic groups in the United Kingdom.

Diabet Med. 1992; 9: 641–5.



ASIA

TRACK

19. Hirsch JE. An index to quantify an individual’s scientific

research output. Proc Natl Acad Sci USA. 2005; 102: 16–

569.

20. Moed HF. Measuring contextual citation impact of sci-

entific journals. J Inform. 2010; 4: 265–77.

21. Rahman M, Fukui T. Biomedical publication: Global

profile and trend. Public Health. 2003; 117: 274–80.

22. Menezes RG, Shankar PV. Has carrying out medical

research in South Asia become easier? Sci Med. 2009; 1:

1–2.

23. International Organizing Committee Council on Health

Research for Development. Report of the International

Conference on Health Research for Development, Bang-

kok, 10–13 October 2000. COHRED, Bangkok, 2000.

24. Michaud CM, Murray CJ, Bloom BR. Burden of disease:

Implications for future research. JAMA. 2001; 285: 535–9.

25. Callaham M, Wears RL, Weber E. Journal prestige, pub-

lication bias, and other characteristics associated with

citation of published studies in peer-reviewed journals.

JAMA. 2002; 287: 2847–50.

26. Filion KB, Pless IB. Factors related to the frequency

of citation of epidemiologic publications. Epidemiol

Perspect Innov. 2008; 5: 3.

27. Chatterjee P. Clinical trials in India: Ethical concerns.

Bull World Health Organ. 2008; 86: 581–2.

28. Jacso P. As we may search: Comparison of major

features of the Web of Science, Scopus, and Google

Scholar citation-based and citation-enhanced databases.

Curr Sci. 2005; 89: 1537–42.

29. Jacso P. The pros and cons of computing the h-index

using Scopus. Online Info Rev. 2008; 32: 524–35.



ASIA

TRACK

diabetes mellitus in south asia: scientific evaluation of the research output...

Documents