Effects of dietary and physical activity interventions on the risk of type 2 diabetes in South Asians: meta-analysis of individual participant data from randomised controlled trials
Individuals of South Asian origin have a high risk of type 2 diabetes and of dying from a diabetes-attributable cause. Lifestyle modification intervention trials to prevent type 2 diabetes in high-risk South Asian adults have suggested more modest effects than in European-origin populations. The strength of the evidence of individual studies is limited, however. We performed an individual participant data meta-analysis of available RCTs to assess the effectiveness of lifestyle modification in South Asian populations worldwide.
We searched PubMed, EMBASE, Cochrane Library and Web of Science (to 24 September 2018) for RCTs on lifestyle modification interventions incorporating diet and/or physical activity in South Asian adults. Reviewers identified eligible studies and assessed the quality of the evidence. We obtained individual participant data on 1816 participants from all six eligible trials (four from Europe and two from India). We generated HR estimates for incident diabetes (primary outcome) and mean differences for fasting glucose, 2 h glucose, weight and waist circumference (secondary outcomes) using mixed-effect meta-analysis overall and by pre-specified subgroups. We used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system to rate the quality of evidence of the estimates. The study is registered with the International Prospective Register of Systematic Reviews ([PROSPERO] CRD42017078003).
Incident diabetes was observed in 12.6% of participants in the intervention groups and in 20.0% of participants in the control groups. The pooled HR for diabetes incidence was 0.65 (95% CI 0.51, 0.81; I2 = 0%) in intervention compared with control groups. The absolute risk reduction was 7.4% (95% CI 4.0, 10.2), with no interactions for the pre-specified subgroups (sex, BMI, age, study duration and region where studies were performed). The quality of evidence was rated as moderate. Mean difference for lifestyle modification vs control groups for 2 h glucose was −0.34 mmol/l (95% CI −0.62, −0.07; I2 = 50%); for weight −0.75 kg (95% CI −1.34, −0.17; I2 = 71%) and for waist −1.16 cm (95% CI −2.16, −0.16; I2 = 75%). No effect was found for fasting glucose. Findings were similar across subgroups, except for weight for European vs Indian studies (−1.10 kg vs −0.08 kg, p = 0.02 for interaction).
Despite modest changes for adiposity, lifestyle modification interventions in high-risk South Asian populations resulted in a clinically important 35% relative reduction in diabetes incidence, consistent across subgroups. If implemented on a large scale, lifestyle modification interventions in high-risk South Asian populations in Europe would reduce the incidence of diabetes in these populations.
KeywordsDiet Individual participant data meta-analysis Lifestyle intervention Physical activity Prevention RCT South Asians Type 2 diabetes
Academic Medical Center
Diabetes Intervention Study in Hindustani Surinamese
Grading of Recommendations, Assessment, Development and Evaluation
Number needed to treat
Prevention of Diabetes and Obesity in South Asians
International Prospective Register of Systematic Reviews
We thank F.S. van Etten-Jamaludin (clinical librarian, Amsterdam UMC, location Academic Medical Center [AMC]) for her help with the development of the search strategy for the different databases. We also thank M. Nicolaou (AMC) and S. Quereshi (Norwegian Centre for Migration and Minority Health, Norwegian Institute of Public Health, Oslo, Norway) for their contribution to the systematic review data collection on which the present study builds .
Some of the data were presented as an abstract at the 54th Annual Meeting of the EASD in Berlin, 2018 (S160, Abstract 317).
The present study builds on a previous systematic review in which the corresponding author was involved. RSB, KS and IGMvV conceived and initiated the meta-analysis and AKJ and IGMvV designed the current study. All authors (except RSB) involved in designing, and agreed on, the protocol for analysis. MM and IGMvV screened abstracts and later full-text studies for eligibility. MM, IGMvV and CAC-M assessed the quality of eligible studies. Data were acquired by IB and IM. IGMvV, KS, AR, MK, EA, AD, GC and AS contributed data to the study and verified preliminary results for their respective studies. IB, IM and KRR analysed the data and, together with AKJ, POV and IGMvV, interpreted the initial results. AKJ and IGMvV drafted the manuscript, with input from MM, IB, IM and POV. All authors contributed to the interpretation of data, critically revised the manuscript and approved the last version for publication. IB, IM, KRR and AKJ had full access to all the data in the study. AKJ is responsible for the integrity of the work as a whole.
The work was sponsored by the Health Program 2014-2020 from the European Union, grant number 664609 HPPJ-2014, set up to improve the prevention of diabetes in South Asians, and by the authors’ institutions: University of Oslo, Oslo, Norway (AKJ, IM, POV); Oslo Metropolitan University, Oslo, Norway (IB, KRR); and Amsterdam UMC, location AMC, University of Amsterdam, the Netherlands (MM, EB, KS, IGMvV). The funders had no role in study design, data collection, analysis, data interpretation or writing of the paper. No pharmaceutical companies or representatives have been involved.
Duality of interest
The authors declare that there is no duality of interest associated with this manuscript. Some authors contributed to studies that were included in this systematic review. JMRG, NS, RSB, AD and AS were co-authors on the Prevention of Diabetes and Obesity in South Asians (PODOSA) trial but were not involved in its evaluation in the present study. IGMvV and KS contributed to the Diabetes Intervention Study in Hindustani Surinamese (DHIAAN), and were therefore not involved in the quality assessment in the present study. Similarly, no other co-authors who contributed their data (AR, MK, EA) were involved in the quality assessment in the present study.
- 2.Jenum AK, Diep LM, Holmboe-Ottesen G, Holme IM, Kumar BN, Birkeland KI (2012) Diabetes susceptibility in ethnic minority groups from Turkey, Vietnam, Sri Lanka and Pakistan compared with Norwegians - the association with adiposity is strongest for ethnic minority women. BMC Public Health 12(1):150. https://doi.org/10.1186/1471-2458-12-150 CrossRefPubMedPubMedCentralGoogle Scholar
- 4.Raymond NT, Varadhan L, Reynold DR et al (2009) Higher prevalence of retinopathy in diabetic patients of South Asian ethnicity compared with white Europeans in the community: a cross-sectional study. Diabetes Care 32(3):410–415. https://doi.org/10.2337/dc08-1422 CrossRefPubMedPubMedCentralGoogle Scholar
- 12.Ramachandran A, Snehalatha C, Mary S et al (2006) The Indian Diabetes Prevention Programme shows that lifestyle modification and metformin prevent type 2 diabetes in Asian Indian subjects with impaired glucose tolerance (IDPP-1). Diabetologia 49(2):289–297. https://doi.org/10.1007/s00125-005-0097-z CrossRefGoogle Scholar
- 14.Galaviz KI, Weber MB, Straus A, Haw JS, Narayan KMV, Ali MK (2018) Global diabetes prevention interventions: a systematic review and network meta-analysis of the real-world impact on incidence, weight, and glucose. Diabetes Care 41(7):1526–1534. https://doi.org/10.2337/dc17-2222 CrossRefPubMedGoogle Scholar
- 15.Admiraal WM, Vlaar EM, Nierkens V et al (2013) Intensive lifestyle intervention in general practice to prevent type 2 diabetes among 18 to 60-year-old South Asians: 1-year effects on the weight status and metabolic profile of participants in a randomized controlled trial. PLoS One 8(7):e68605. https://doi.org/10.1371/journal.pone.0068605 CrossRefPubMedPubMedCentralGoogle Scholar
- 16.Bhopal RS, Douglas A, Wallia S et al (2014) Effect of a lifestyle intervention on weight change in south Asian individuals in the UK at high risk of type 2 diabetes: a family-cluster randomised controlled trial. Lancet Diabetes Endocrinol 2(3):218–227. https://doi.org/10.1016/S2213-8587(13)70204-3 CrossRefGoogle Scholar
- 17.Telle-Hjellset V, Kjollesdal MKR, Bjorge B et al (2013) The InnvaDiab-DE-PLAN study: a randomised controlled trial with a culturally adapted education programme improved the risk profile for type 2 diabetes in Pakistani immigrant women. Br J Nutr 109(3):529–538. https://doi.org/10.1017/S000711451200133X CrossRefPubMedGoogle Scholar
- 18.Andersen E, Burton NW, Anderssen SA (2012) Physical activity levels six months after a randomised controlled physical activity intervention for Pakistani immigrant men living in Norway. Int J Behav Nutr Phys Act 9(1):47. https://doi.org/10.1186/1479-5868-9-47 CrossRefPubMedPubMedCentralGoogle Scholar
- 19.Brown T, Smith S, Bhopal R, Kasim A, Summerbell C (2015) Diet and physical activity interventions to prevent or treat obesity in South Asian children and adults: a systematic review and meta-analysis. Int J Environ Res Public Health 12(1):566–594. https://doi.org/10.3390/ijerph120100566 CrossRefPubMedPubMedCentralGoogle Scholar
- 23.Thomas H (2003) Quality assessment tool for quantitative studies: effective public health practice project. McMaster University, Hamilton, ON, CanadaGoogle Scholar
- 26.Ramachandran A, Snehalatha C, Ram J et al (2013) Effectiveness of mobile phone messaging in prevention of type 2 diabetes by lifestyle modification in men in India: a prospective, parallel-group, randomised controlled trial. Lancet Diabetes Endocrinol 1(3):191–198. https://doi.org/10.1016/S2213-8587(13)70067-6 CrossRefPubMedGoogle Scholar
- 28.WHO Expert Consultation (2004) Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies. Lancet 363(9403):157–163Google Scholar
- 29.Koopman L, van der Heijden GJ, Grobbee DE, Rovers MM (2008) Comparison of methods of handling missing data in individual patient data meta-analyses: an empirical example on antibiotics in children with acute otitis media. Am J Epidemiol 167(5):540–545. https://doi.org/10.1093/aje/kwm341 CrossRefPubMedGoogle Scholar
- 31.Royston P, White IR (2011) Multiple imputation by chained equations (MICE): implementation in Stata. J Stat Softw 45(5):1–20Google Scholar
- 35.Snehalatha C, Mary S, Joshi VV, Ramachandran A (2008) Beneficial effects of strategies for primary prevention of diabetes on cardiovascular risk factors: results of the Indian Diabetes Prevention Programme. Diab Vasc Dis Res 5(1):25–29. https://doi.org/10.3132/dvdr.2008.005 CrossRefPubMedGoogle Scholar
- 36.Snehalatha C, Mary S, Selvam S et al (2009) Changes in insulin secretion and insulin sensitivity in relation to the glycemic outcomes in subjects with impaired glucose tolerance in the Indian Diabetes Prevention Programme-1 (IDPP-1). Diabetes Care 32(10):1796–1801. https://doi.org/10.2337/dc09-0676 CrossRefPubMedPubMedCentralGoogle Scholar
- 37.Ramachandran A, Arun N, Shetty AS, Snehalatha C (2010) Efficacy of primary prevention interventions when fasting and postglucose dysglycemia coexist: analysis of the Indian Diabetes Prevention Programmes (IDPP-1 and IDPP-2). Diabetes Care 33(10):2164–2168. https://doi.org/10.2337/dc09-1150 CrossRefPubMedPubMedCentralGoogle Scholar
- 38.Patel JV, Hughes EA, Lip GY, Gill PS (2011) Diabetes Health, Residence & Metabolism in Asians: the DHRMA study, research into foods from the Indian subcontinent - a blinded, randomised, placebo controlled trial. BMC Cardiovasc Disord 11(1):70. https://doi.org/10.1186/1471-2261-11-70 CrossRefPubMedPubMedCentralGoogle Scholar
- 43.Wijesuriya M, Fountoulakis N, Guess N et al (2017) A pragmatic lifestyle modification programme reduces the incidence of predictors of cardio-metabolic disease and dysglycaemia in a young healthy urban South Asian population: a randomised controlled trial. BMC Med 15(1):146. https://doi.org/10.1186/s12916-017-0905-6 CrossRefPubMedPubMedCentralGoogle Scholar
- 44.Yates T, Davies M, Gorely T, Bull F, Khunti K (2009) Effectiveness of a pragmatic education programme aimed at promoting walking activity in individuals with impaired glucose tolerance: a randomized controlled trial. Diabetes Care 32(8):1404–1410. https://doi.org/10.2337/dc09-0130 CrossRefPubMedPubMedCentralGoogle Scholar
- 47.Patel S, Bhopal R, Unwin N, White M, Alberti KG, Yallop J (2001) Mismatch between perceived and actual overweight in diabetic and non-diabetic populations: a comparative study of South Asian and European women. J Epidemiol Community Health 55(5):332–333. https://doi.org/10.1136/jech.55.5.332 CrossRefPubMedPubMedCentralGoogle Scholar
- 48.Hussain A, Bjorge B, Hjellset VT, Holmboe-Ottesen G, Wandel M (2010) Body size perceptions among Pakistani women in Norway participating in a controlled trial to prevent deterioration of glucose tolerance. Ethn Health 15(3):237–251. https://doi.org/10.1080/13557851003668148 CrossRefPubMedGoogle Scholar
- 52.Nierkens V, Hartman MA, Nicolaou M et al (2013) Effectiveness of cultural adaptations of interventions aimed at smoking cessation, diet, and/or physical activity in ethnic minorities. a systematic review. PLoS One 8(10):e73373. https://doi.org/10.1371/journal.pone.0073373 CrossRefPubMedPubMedCentralGoogle Scholar
- 53.Iliodromiti S, Ghouri N, Celis-Morales CA, Sattar N, Lumsden MA, Gill JM (2016) Should physical activity recommendations for South Asian adults be ethnicity-specific? Evidence from a cross-sectional study of South Asian and White European men and women. PLoS One 11(8):e0160024. https://doi.org/10.1371/journal.pone.0160024 CrossRefPubMedPubMedCentralGoogle Scholar
- 54.Bhopal RS (2019) Epidemic of cardiovascular disease and diabetes. Explaining the phenomenon in South Asians worldwide. Oxford University Press, Oxford. https://doi.org/10.1093/med/9780198833246.001.0001 CrossRefGoogle Scholar
- 56.Huttunen-Lenz M, Hansen S, Christensen P et al (2018) PREVIEW study-influence of a behavior modification intervention (PREMIT) in over 2300 people with pre-diabetes: intention, self-efficacy and outcome expectancies during the early phase of a lifestyle intervention. Psychol Res Behav Manag 11:383–394. https://doi.org/10.2147/PRBM.S160355 CrossRefPubMedPubMedCentralGoogle Scholar