Young South Asian women in the United Kingdom show evidence of blunted endothelium-dependent dilatation: implications for future cardiovascular disease

Introduction: Prevalence of cardiovascular disease (CVD) is higher in South Asians than white Europeans. The offspring of hypertensive parents (OH) have greater risk of hypertension than offspring of normotensive parents (ON). We hypothesized that endothelium-dependent dilatation is already blunted in young South Asians, relative to young white European women, particularly in South Asian OH women.

Methods: In young white European ON, South Asian ON and OH women (18-25years old; 10 per group) who were normotensive, we recorded cutaneous perfusion by laser Doppler fluximetry during reactive hyperaemia and iontophoresis of acetylcholine (ACh), before and after inhibiting NO synthesis (NOS) or/and cyclooxygenase (COX). In these and an additional 135 age-matched South Asian and white European women, physical activity and life-style factors were assessed by questionnaire.

Results: ACh-evoked dilatation was blunted in young South Asians, relative to white European women. It was attenuated by NOS or COX inhibition in white European ON; by NOS inhibition only in South Asian ON, but not OH women. After combined NOS and COX inhibition, ACh-evoked dilatations were similar to control ACh responses. Similar findings were made for reactive hyperaemia. Questionnaire data indicated young South Asians have lower physical activity levels, fresh fruit and vegetable intake than white European women, South Asian OH being lower than white European ON, or OH women.

Conclusion: Endothelium-dependent dilatation is blunted in young South Asians, relative to white European women, especially in South Asian OH in whom NO-dependent and prostaglandin-dependent dilatation is blunted. We suggest improved diet and greater physical activity could be particularly effective in improving endothelium-dependent dilatation and reducing future CVD risk in young South Asian OH women.