Ghouri N, Purves D, McConnachie A, Wilson J, Gill JMR, Sattar N. Lower cardiorespiratory fitness contributes to increased insulin resistance and fasting glycaemia in middle-aged South Asian compared with European men living in the UK.
Diabetologia 2013;
56:2238-49. [PMID:
23811809 PMCID:
PMC3764328 DOI:
10.1007/s00125-013-2969-y]
[Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 05/17/2013] [Indexed: 02/06/2023]
Abstract
AIMS/HYPOTHESIS
This study aimed to determine the extent to which increased insulin resistance and fasting glycaemia in South Asian men, compared with white European men, living in the UK, was due to lower cardiorespiratory fitness (maximal oxygen uptake [VO(2max)]) and physical activity.
METHODS
One hundred South Asian and 100 age- and BMI-matched European men without diagnosed diabetes, aged 40-70 years, had fasted blood taken for measurement of glucose concentration, HOMA-estimated insulin resistance (HOMA(IR)), plus other risk factors, and underwent assessment of physical activity (using accelerometry), VO(2max), body size and composition, and demographic and other lifestyle factors. For 13 South Asian and one European man, HbA1c levels were >6.5% (>48 mmol/mol), indicating potential undiagnosed diabetes; these men were excluded from the analyses. Linear regression models were used to determine the extent to which body size and composition, fitness and physical activity variables explained differences in HOMA(IR) and fasting glucose between South Asian and European men.
RESULTS
HOMA(IR) and fasting glucose were 67% (p < 0.001) and 3% (p < 0.018) higher, respectively, in South Asians than Europeans. Lower VO(2max), lower physical activity and greater total adiposity in South Asians individually explained 68% (95% CI 45%, 91%), 29% (11%, 46%) and 52% (30%, 80%), respectively, and together explained 83% (50%, 119%) (all p < 0.001) of the ethnic difference in HOMA(IR). Lower VO(2max) and greater total adiposity, respectively, explained 61% (9%, 111%) and 39% (9%, 76%) (combined effect 63% [8%, 115%]; all p < 0.05) of the ethnic difference in fasting glucose.
CONCLUSIONS/INTERPRETATION
Lower cardiorespiratory fitness is a key factor associated with the excess insulin resistance and fasting glycaemia in middle-aged South Asian, compared with European, men living in the UK.
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