Adult height and glucose tolerance: a re-appraisal of the importance of body mass index.

AIM: To study both the association between adult height and glucose regulation based on findings from a 75-g oral glucose tolerance test, and the combined effect of height and adiposity on glucose values.

METHODS: We conducted a population-based, cross-sectional study among apparently healthy people with high cardiovascular risk living in south-western Finland. The study included 2659 participants aged 45-70 years, who had at least one cardiovascular risk factor but no previously diagnosed diabetes or manifested cardiovascular disease. An oral glucose tolerance test was performed in all participants. Height and weight were measured and BMI was calculated. The participants were divided into five height groups based on normal distribution. For further analysis of the association between height and glucose concentrations the participants were divided into four BMI groups (<25.0 kg/m2 ; 25-29.9 kg/m2 ; 30-34.9 kg/m2 ; ≥35 kg/m2 ). Data were analysed using age-adjusted linear regression models.

RESULTS: Height was inversely associated with 2-h plasma glucose, but not with fasting plasma glucose concentration. No gender difference was observed. The 2-h plasma glucose values increased with an increase in BMI, so that height was inversely associated with 2-h plasma glucose in the three lowest BMI groups, but not in the highest BMI group (P=0.33).

CONCLUSIONS: Taller people had lower 2-h plasma glucose concentrations than shorter people, up to a BMI of 35 kg/m2 . Adjustment for height and BMI is needed for accurate interpretation of oral glucose tolerance tests.