Meta-Analysis
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Diabetes. Jan 15, 2018; 9(1): 40-52
Published online Jan 15, 2018. doi: 10.4239/wjd.v9.i1.40
Association of obesity with hypertension and type 2 diabetes mellitus in India: A meta-analysis of observational studies
Giridhara R Babu, G V S Murthy, Yamuna Ana, Prital Patel, R Deepa, Sara E Benjamin-Neelon, Sanjay Kinra, K Srinath Reddy
Giridhara R Babu, Yamuna Ana, R Deepa, Public Health Foundation of India, IIPH-H, Bangalore Campus, SIHFW Premises, Beside Leprosy Hospital, Bangalore 560023, India
G V S Murthy, Indian Institute of Public Health-Hyderabad, Plot # 1, A.N.V.Arcade, Amar Co-op Society, Kavuri Hills, Madhapur, Hyderabad 500033, India
G V S Murthy, London School of Hygiene and Tropical Medicine, London WC1E 7HT, United Kingdom
Prital Patel, Indian School of Business, Hyderabad 500111, India
Sara E Benjamin-Neelon, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, United States
Sanjay Kinra, Department of Non-Communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine and University College London Hospital, London WC1E 7HT, United Kingdom
K Srinath Reddy, Public Health Foundation of India, ISID Campus, 4 Institutional Area Vasant Kunj, New Delhi 110070, India
Author contributions: Babu GR conceived the study aims and design, contributed to the data extraction, planned the analysis, interpreted the results and drafted the final version of the paper; Murthy GVS has contributed to manuscript development and critical review; Ana Y and Deepa R evaluated the study articles and made decisions on inclusion and exclusion of the articles; Patel P was involved in manuscript development, provided inputs for estimations and critical review; Neelon SEB has reviewed the manuscript critically; Kinra S has contributed to the article critically for important intellectual content; Reddy KS has contributed to the article critically for important intellectual content and final approval of the version to be published.
Supported by Wellcome Trust DBT India Alliance Intermediate Fellowship (Clinical and Public Health) to Giridhara R Babu.
Conflict-of-interest statement: The authors deny any conflict of interest.
Data sharing statement: All data generated or analysed during this study are included in this published article. No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Giridhara R Babu, MBBS, MBA, MPH, PhD, Wellcome Trust-DBT India alliance Research Fellow in Public Health, Additional Professor, Public Health Foundation of India, IIPH-H, Bangalore Campus, SIHFW Premises, Beside Leprosy Hospital, 1st Cross, Magadi Road, Bangalore 560023, India. giridhar@iiphh.org
Telephone: +91-080-23206124
Received: August 3, 2017
Peer-review started: August 7, 2017
First decision: September 7, 2017
Revised: November 5, 2017
Accepted: November 19, 2017
Article in press: November 19, 2017
Published online: January 15, 2018
ARTICLE HIGHLIGHTS
Research background

It is well known that hypertension and type 2 diabetes mellitus (T2DM) are the major non-communicable diseases (NCDs) leading to catastrophic complications and death in India. It is important to investigate the role of modifiable risk factors such as obesity resulting in NCDs. The authors are aware that the risk factors seldom act in isolation and it is important to alleviate the impact of their confluence. It is therefore important to determine the significance of risk contribution by individual risk factor like obesity. Available evidence suggests strong associations between obesity and NCDs. However, none of the earlier reviews have specifically evaluated the role of obesity in the etiology of hypertension and T2DM in India.

Research motivation

As obesity is one of the key NCD’s and risk factor for the majority of other NCD’s in India, the authors need to provide evidence to show its association with other major diseases like hypertension and T2DM. By exhibiting the evidence and its association, preventive measures can be taken for route cause of disease.

Research objectives

To perform a meta-analysis of the association of obesity with hypertension and T2DM in India among adults to assess potential causal factors and improve prevention and control measures for these NCDs.

Research methods

The authors have followed rigorous methodology in doing comprehensive meta-analysis with a predefined protocol. The authors entered and analysed data using the Cochrane Collaboration’s Review Manager software version 5 for Windows (Cochrane Collaboration, Oxford, England), and subsequently entered into a spreadsheet and re-analysed data using the “metan” command of STATA 11 version for Mac. The authors have used the RevMan for developing flow chart according PRISMA guidelines, and also assessed the methodological quality of studies. The authors found that the pooled estimate between obesity and hypertension and the heterogeneity around this estimate which indicating low variability among the included studies. The pooled estimate from all studies showed a statistically significant association between obesity and T2DM. The authors observed considerable heterogeneity among these estimates of studies.

Research results

The results shows that the association of obesity and hypertension is strongly positive and T2DM moderately positive compared with healthy non-obese adults in India. This study provides evidence regarding the putative role of obesity and its impact on NCDs. This also coincides with the observed trend of increasing prevalence of hypertension in India across different risk groups for obesity.

Research conclusions

The current stage of the obesity epidemic presents an opportunity for policy and intervention efforts related to prevention. This opportunity necessitates developing a clear strategy for the control of NCDs through rigorous program management at national and state levels. The increasing prevalence of obesity, hypertension, and diabetes in India has enormous implications for the healthcare system. Policy makers, government officials, and public health professionals can focus policy and intervention efforts on obesity as an important risk factor to prevent NCDs like diabetes and hypertension.

Research perspectives

Study provides with experience of route cause associated with major NCD’s like hypertension and T2DM. As the evidence suggested obesity is associated with these NCD’s, it is the time to think regarding preventive aspect of obesity to prevent future outcome. With limited earlier statistically proved evidence, the current meta-analysis the association of obesity with hypertension and T2DM in India proved the statistical significance association of obesity with major NCD’s such as T2DM and hypertension with high degree of variability and substantial heterogeneity. Results provided the possible common risk factors for the NCD’s and made a way for the researchers to think of the research on interventional measures to prevent obesity in coming future. Research involving Randomized Controlled Trials nested within cohort for the prevention of obesity will provide affirmation of fruitful interventions which can be included in future evidence based policy formulation.