The effect of prior walking on coronary heart disease risk markers in South Asian and European men.

Purpose: Heart disease risk is elevated in South Asians possibly due to impaired postprandial metabolism. Running has been shown to induce greater reductions in postprandial lipaemia in South Asian than European men but the effect of walking in South Asians is unknown. Methods: Fifteen South Asian and 14 White European men aged 19-30 years completed two, 2-d trials in a randomised crossover design. On day 1, participants rested (control) or walked for 60 min at approximately 50% maximum oxygen uptake (exercise). On day 2, participants rested and consumed two high fat meals over a 9h period during which 14 venous blood samples were collected. Results: South Asians exhibited higher postprandial triacylglycerol (geometric mean (95% confidence interval) 2.29(1.82 to 2.89) vs. 1.54(1.21 to 1.96) mmol·L-1·hr-1), glucose (5.49(5.21 to 5.79) vs. 5.05(4.78 to 5.33) mmol·L-1·hr-1), insulin (32.9(25.7 to 42.1) vs. 18.3(14.2 to 23.7) µU·mL-1·hr-1) and interleukin-6 (2.44(1.61 to 3.67) vs. 1.04(0.68 to 1.59) pg·mL-1·hr-1) than Europeans (all ES ≥ 0.72, P≤0.03). Between-group differences in triacylglycerol, glucose and insulin were not significant after controlling for age and percentage body fat. Walking reduced postprandial triacylglycerol (1.79(1.52 to 2.12) vs. 1.97(1.67 to 2.33) mmol·L-1·hr-1) and insulin (21.0(17.0 to 26.0) vs. 28.7(23.2 to 35.4) µU·mL-1·hr-1) (all ES ≥ 0.23. P≤0.01), but group differences were not significant. Conclusions: Healthy South Asians exhibited impaired postprandial metabolism compared with White Europeans, but these differences were diminished after controlling for potential confounders. The small-moderate reduction in postprandial triacylglycerol and insulin after brisk walking was not different between the ethnicities

Exercise and Coronary Heart Disease Risk Markers in South Asian and European Men

This is a non-final version of an article published in final form in: ARJUNAN, S.P. ... (et al.), 2013. Exercise and coronary heart disease risk markers in South Asian and European men. Medicine and Science in Sports and Exercise, 45 (7), pp. 1261-1268. URL: http://dx.doi.org/10.1249/MSS.0b013e3182853ecf.PURPOSE: South Asians have a higher than average risk of coronary heart disease. The reasons for this are unclear but physical inactivity and/or poor responsiveness to exercise may play a role. This study compared the effect of prior exercise on postprandial triacylglycerol (TAG), glucose, insulin, interleukin-6 (IL-6) and soluble intercellular adhesion molecule-1 (sICAM-1) concentrations in South Asian and European men. METHODS: Ten healthy South Asian men (i.e. nine Indian men and one Pakistani man) and 10 healthy European men aged 20 to 28 years completed two, 2-day trials (exercise and control) in a randomised-crossover design. On the afternoon of day 1 of the exercise trial, participants ran on a treadmill for 60 minutes at approximately 70% of maximal oxygen uptake. Participants rested on day 1 of the control trial. On day 2 of both trials participants rested and consumed high fat (57% of energy content) test meals for breakfast (0 h) and lunch (4 h). Fourteen venous blood samples were collected from a cannula between 0 h and 9 h for metabolic measurements. RESULTS: Three-way ANOVA identified higher (P < 0.05) postprandial TAG and insulin concentrations in South Asian versus European men. Exercise lowered postprandial TAG and IL-6 and elevated sICAM-1 concentrations. An interaction effect indicated a greater decrease (22 versus 10%) in TAG area under the concentration versus time curve after exercise in South Asian than European men. CONCLUSIONS: Postprandial TAG and insulin responses to high fat meals were elevated in these South Asian men but acute exercise was equally if not more effective for reducing postprandial lipemia in South Asian than in European men