Abstract P232: Worse Cardiometabolic Health in African Immigrants than African-Americans: Reconsideration of the Healthy Immigrant Effect
In decades past, African immigrants were considered to have better cardiometabolic health than African Americans. Whether this health advantage continues to exist in the 21st century is unknown. To explore differences in markers of cardiometabolic health, oral glucose tolerance tests, blood pressure (BP), visceral adipose tissue (VAT) volume and the waist circumference (WC) which predicts insulin resistance were compared in 210 men (134 African immigrants, 76 African Americans, mean age 36±9y (mean±SD), range 20-64y) who self-identified as healthy. Insulin resistance was defined by the lowest quartile of the insulin sensitivity index (SI≤2•28mU/L-1.min-1). Receiver operating characteristic curves and the Youden Index were used to identify the WC which optimally predicts insulin resistance. BMI was lower in African immigrants than African Americans (27.4±3.9 vs. 29.3±5.5kg/m2, P<0.01). Adjusting for BMI, WC did not differ between groups (93±5 vs. 94±5cm, P=0.55); but African immigrants had more visceral adipose tissue (VAT) (P<0.001) higher BP (P≤0.01), higher fasting glucose (P≤0.001) and 2h glucose (P<0.001) as well as a higher prevalence of previously undiagnosed diabetes (7% (9 of 134) vs. 0% (0 of 76), P<0.01) and pre-diabetes (35% (47 of 134) vs. 22% (17 of 76), P<0.01). Degree of insulin resistance did not differ in African immigrants and African Americans (4.17±2.88 vs. 4.24±2.61 (mU/L)-1 .min-1, P=0.88). Yet, the WC which optimally predicted insulin resistance was lower in African immigrants than African Americans, specifically 92 cm and 102 cm, respectively. As African immigrants had higher VAT, BP and glucose levels than African Americans, the healthy immigrant effect may no longer be a valid concept. As insulin resistance occurred at a lower WC in African immigrants than African Americans, lower BMI in African immigrants does not appear to provide protection from cardiometabolic risk.
Author Disclosures: A.E. Sumner: None. M.Y. O'Connor: None. C.K. Thoreson: None. M. Ricks: None. A.B. Courville: None. F. Thomas: None. J. Yao: None. P.T. Katzmarzyk: None.
- © 2014 by American Heart Association, Inc.