Long-term weight change: association with impaired glucose metabolism in young Austrian adults

Abstract

Little is known about the associations between long-term weight change and the natural history of impaired fasting glucose (IFG) in young adults. We investigated the association between long-term body mass index (BMI) change and the risk of IFG using data of 24,930 20- to 40-year-old participants from the Vorarlberg Health Monitoring and Promotion Program (VHM&PP) cohort. Poisson models were applied to estimate the 10-year risk for new development of IFG (≥ 5.6 mmol/L), and persistence of IFG. Over 10 years, most men (68.2%) and women (70.0%) stayed within their initial BMI category. The risk for incident IFG was highest for men and women with persisting obesity (37.4% and 24.1%) and lowest with persisting normal weight (15.7% and 9.3%). Men transitioning from normal to overweight increased their risk of incident IFG by factor 1.45 (95%-CI: 1.31, 1.62), women by 1.70 (95%-CI: 1.50, 1.93), whereas transitioning from overweight to normal weight decreased the risk in men by 0.69 (95%-CI: 0.53, 0.90) and 0.94 (95%-CI: 0.66, 1.33) in women. Relative risks for men and women transitioning from obesity to overweight were 0.58 and 0.44, respectively. In conclusion, 10 year weight increase was associated with an increased IFG risk, weight decrease with a decreased risk of IFG in young adults.

Fig 1. IFG risk by BMI category and category change.

Absolute risk (AR) for development and persistence of impaired fasting glucose by BMI category, and relative risk (RR), risk difference (RD) associated with upward or downward change in BMI category for 30 year old women and men.

Fig 2. IFG risk by baseline BMI and BMI change estimated using generalized additive models.

Absolute risk for development (a: men, b: women) and persistence (c: men, d: women) of impaired fasting glucose (IFG) by baseline BMI (y-axis) and ∆BMI (x-axis) for 30 year old individuals. Green indicates a low, yellow intermediate and red high risk. Contour lines (red lines) represent combinations of baseline BMI and BMI change being associated with the same risk. For example when looking at Fig 2a, at the “0.15” contour line (representing a 15% risk): There are men with a low baseline BMI and small BMI increase, and there are men with a high baseline BMI and pronounced weight decrease. Those men are at the same risk for development of IFG. Rather horizontal contour lines indicate baseline BMI is more strongly associated with IFG risk, rather vertical contour lines indicate BMI change is more strongly associated with IFG risk.