Rishi Caleyachetty1, Thomas M Barber2, Nuredin Ibrahim Mohammed3, Francesco P Cappuccio4, Rebecca Hardy5, Rohini Mathur6, Amitava Banerjee7, Paramjit Gill4. 1. Nuffield Department of Population Health, University of Oxford, Oxford, UK; Warwick Medical School, University of Warwick, Coventry, UK. Electronic address: r.caleyachetty@icloud.com. 2. Warwick Medical School, University of Warwick, Coventry, UK; Warwickshire Institute for the Study of Diabetes, Endocrinology and Metabolism, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK. 3. MRC Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia. 4. Warwick Medical School, University of Warwick, Coventry, UK. 5. Social Research Institute, University College London, London, UK. 6. Department of Non-Communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK. 7. Institute of Health Informatics, University College London, London, UK.
Abstract
BACKGROUND: National and global recommendations for BMI cutoffs to trigger action to prevent obesity-related complications like type 2 diabetes among non-White populations are questionable. We aimed to prospectively identify ethnicity-specific BMI cutoffs for obesity based on the risk of type 2 diabetes that are risk-equivalent to the BMI cutoff for obesity among White populations (≥30 kg/m2). METHODS: In this population-based cohort study, we used electronic health records across primary care (Clinical Practice Research Datalink) linked to secondary care records (Hospital Episodes Statistics) from a network of general practitioner practices in England. Eligible participants were aged 18 years or older, without any past or current diagnosis of type 2 diabetes, had a BMI of 15·0-50·0 kg/m2 and complete ethnicity data, were registered with a general practitioner practice in England at any point between Sept 1, 1990, and Dec 1, 2018, and had at least 1 year of follow-up data. Patients with type 2 diabetes were identified by use of a CALIBER phenotyping algorithm. Self-reported ethnicity was collapsed into five main categories. Age-adjusted and sex-adjusted negative binomial regression models, with fractional polynomials for BMI, were fitted with incident type 2 diabetes and ethnicity data. FINDINGS: 1 472 819 people were included in our study, of whom 1 333 816 (90·6%) were White, 75 956 (5·2%) were south Asian, 49 349 (3·4%) were Black, 10 934 (0·7%) were Chinese, and 2764 (0·2%) were Arab. After a median follow-up of 6·5 years (IQR 3·2-11·2), 97 823 (6·6%) of 1 472 819 individuals were diagnosed with type 2 diabetes. For the equivalent age-adjusted and sex-adjusted incidence of type 2 diabetes at a BMI of 30·0 kg/m2 in White populations, the BMI cutoffs were 23·9 kg/m2 (95% CI 23·6-24·0) in south Asian populations, 28·1 kg/m2 (28·0-28·4) in Black populations, 26·9 kg/m2 (26·7-27·2) in Chinese populations, and 26·6 kg/m2 (26·5-27·0) in Arab populations. INTERPRETATION: Revisions of ethnicity-specific BMI cutoffs are needed to ensure that minority ethnic populations are provided with appropriate clinical surveillance to optimise the prevention, early diagnosis, and timely management of type 2 diabetes. FUNDING: National Institute for Health Research.
BACKGROUND: National and global recommendations for BMI cutoffs to trigger action to prevent obesity-related complications like type 2 diabetes among non-White populations are questionable. We aimed to prospectively identify ethnicity-specific BMI cutoffs for obesity based on the risk of type 2 diabetes that are risk-equivalent to the BMI cutoff for obesity among White populations (≥30 kg/m2). METHODS: In this population-based cohort study, we used electronic health records across primary care (Clinical Practice Research Datalink) linked to secondary care records (Hospital Episodes Statistics) from a network of general practitioner practices in England. Eligible participants were aged 18 years or older, without any past or current diagnosis of type 2 diabetes, had a BMI of 15·0-50·0 kg/m2 and complete ethnicity data, were registered with a general practitioner practice in England at any point between Sept 1, 1990, and Dec 1, 2018, and had at least 1 year of follow-up data. Patients with type 2 diabetes were identified by use of a CALIBER phenotyping algorithm. Self-reported ethnicity was collapsed into five main categories. Age-adjusted and sex-adjusted negative binomial regression models, with fractional polynomials for BMI, were fitted with incident type 2 diabetes and ethnicity data. FINDINGS: 1 472 819 people were included in our study, of whom 1 333 816 (90·6%) were White, 75 956 (5·2%) were south Asian, 49 349 (3·4%) were Black, 10 934 (0·7%) were Chinese, and 2764 (0·2%) were Arab. After a median follow-up of 6·5 years (IQR 3·2-11·2), 97 823 (6·6%) of 1 472 819 individuals were diagnosed with type 2 diabetes. For the equivalent age-adjusted and sex-adjusted incidence of type 2 diabetes at a BMI of 30·0 kg/m2 in White populations, the BMI cutoffs were 23·9 kg/m2 (95% CI 23·6-24·0) in south Asian populations, 28·1 kg/m2 (28·0-28·4) in Black populations, 26·9 kg/m2 (26·7-27·2) in Chinese populations, and 26·6 kg/m2 (26·5-27·0) in Arab populations. INTERPRETATION: Revisions of ethnicity-specific BMI cutoffs are needed to ensure that minority ethnic populations are provided with appropriate clinical surveillance to optimise the prevention, early diagnosis, and timely management of type 2 diabetes. FUNDING: National Institute for Health Research.
Authors: Kushala W M Abeysekera; James G Orr; Fiona H Gordon; Laura D Howe; Julian Hamilton-Shield; Jon Heron; Matthew Hickman Journal: BMC Gastroenterol Date: 2022-06-30 Impact factor: 2.847