Does age, sex, or ACE genotype affect glucose and insulin responses to strength training?

Abstract

The purpose of the present study was to determine whether age, sex, or angiotensin I-converting enzyme (ACE) genotype influences the effects of strength training (ST) on glucose homeostasis. Nineteen sedentary young (age = 20–30 yr) men ( n = 10) and women ( n = 9) were studied and compared with 21 sedentary older (age = 65–75 yr) men ( n = 12) and women ( n = 9) before and after a 6-mo total body ST program. Fasting insulin concentrations were reduced in young men and in older men with ST ( P< 0.05 in both). In addition, total insulin area under the curve decreased by 21% in young men ( P < 0.05), and there was a trend for a decrease (11%) in older men ( P = 0.06). No improvements in insulin responses were observed in young or older women. The ACE deletion/deletion genotype group had the lowest fasting insulin and insulin areas under the oral glucose tolerance test (OGTT) curve before training (all P < 0.05), but those with at least one insertion allele had a trend for a greater reduction in total insulin area than deletion homozygotes ( P = 0.07). These results indicate that ST has a more favorable effect on insulin response to an OGTT in men than in women and offer some support for the hypothesis that ACE genotype may influence insulin responses to ST.