Effects on glucose tolerance, insulin secretion, insulin-like growth factor 1 and its binding protein, IGFBP-1, in a randomized controlled diet and exercise study in healthy, middle-aged men.
OBJECTIVES. To study the effects of advice on diet, exercise and their combination on oral glucose tolerance (OGTT), insulin secretion, insulin-like growth factor-1 (IGF-1) and its binding protein, IGFBP-1. DESIGN: A 6-month, randomized, controlled intervention study. SETTING: Primary health care centres in Sollentuna, Stockholm and the Department of Medicine, Karolinska Hospital, Stockholm, Sweden. SUBJECTS. One hundred and fifty-seven normoglycaemic healthy men, mean age 46 years, range 35-60 years, with slightly to moderately raised cardiovascular risk factors. INTERVENTIONS: Advice on diet (D, n = 40), exercise (E, n = 39) a combination of both (DE, n = 39) and a control group (C, n = 39). MAIN OUTCOME MEASURES. An OGTT, insulin secretion, IGF-1 and its binding protein, IGFBP-1. RESULTS. The number of pathological OGTTs in the intervention groups decreased from 42/118 to 33/118 whilst the number in the control group did not change. Fasting insulin levels decreased in groups E and DE from 8.8-7.4 mU L-1 (P