Gestational diabetes, insulin resistance and physical activity in pregnancy in a multi-ethnic population – a public health perspective

Abstract

Aims: To summarize findings from the STORK-Groruddalen Study regarding ethnic differences in the prevalence of gestational diabetes (GDM) by the WHO and modified International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria (no one hour value), insulin resistance, β-cell function and physical activity (PA) level. Methods: Population-based cohort study of 823 healthy pregnant women (59% ethnic minorities). Data from questionnaires, fasting blood samples, anthropometrics and objectively recorded PA level (SenseWear Armband), were collected at <20 (Visit 1) and 28±2 (Visit 2) weeks of gestation. The 75-g OGTT was performed at Visit 2. Insulin resistance (HOMA-IR) and β-cell function (HOMA-β) were estimated from venous fasting plasma glucose and C-peptide. Results: The GDM prevalence was 13.0% with the WHO and 31.5% with the IADPSG criteria. The ethnic minority women, especially South Asians, had highest figures. South and East Asian women had highest HOMA-IR at Visit 1 after adjustment for BMI. HOMA-IR increased from Visit 1 to Visit 2 irrespective of ethnic origin. Compared with Western European women, the absolute and percentage increase in HOMA-β from Visit 1 to Visit 2 was poorest for the South and East Asian women. All ethnic groups walked less and spent less time in moderate-to-vigorous physical activity (MVPA) during weekend days compared with weekdays. South Asian women were least active, measured by steps and by time spent in MVPA. Conclusion: Alarmingly high rates of GDM were found, highest among South Asians. South Asian women were less physically active, more insulin resistant and showed poorer β-cell compensation compared with Western Europeans.