Ethnic differences in glucose tolerance: the diet (fatty acid) rather than genetic variation

ABSTRACT

This study examined the possible role of plasma fatty acids (FA) and serum lipid composition in ethnic differences in glucose tolerance (GT). In carefully taken population samples (77 percent response) aged 45-74 years, 75 g GT test results were compared between 100 African-Caribbeans (AfC) [53 women (w)], 188 white Europeans (60w) and 113 Gujratis (55w), excluding known diabetics. 2 hr normoglycaemic (ng) AfC (n=70) had considerably lower age and sex adjusted fasting non-esterified (NE) FA at 0.42 (mean, 95 percent CI 0.36-0.48) mmol/l vs 0.58 (0.52-0.64) mmol/l in Europeans and 0.58 (0.51-0.65) mmol/l in Gujratis (F=8.2, p=0.0004). NEfA were significantly (26-52 percent) greater in, with no ethnic difference between, glucose intolerants (GIT). Gujratis had higher proportion of serum linoleate (18.2n-6) at 35.3 (34-36.6 percent) than AfC (27.4, 26-29 percent) or whites (24, 23-26 percent) but half or less of docosahexanoate (226n-3) - 1.2(0.8-15)percent vs 2.7(2.3-3) percent and 2.4(2-2.8) percent in both ng and GIT groups. With BMI and insulin, NEFA were independently associated with 2 hr glucose accounting for much of the ethnic difference.(AU)