Aim: Previous studies have shown that individuals with type 2 diabetes (T2D) and impaired glucose tolerance (IGT) have lower self-rated health than normoglycemic individuals. Less is known about individuals with impaired fasting glucose (IFG). The aim of this study was to examine differences in self-rated health between individuals with IGT and those with IFG, taking into account the mediating effect of lifestyle.
Methods: In 2002-2005, a total of 2816 individuals 35-74 years were randomly selected for a population-based study in the southwest of Sweden (The Skaraborg Project). All participants performed an oral glucose tolerance test (OGTT) and had anthropometric measurements and blood pressure taken. Fasting venous blood samples were drawn and validated questionnaires on lifestyles were completed. Self-rated health (SRH) was ranked on a five-graded scale, and dichotomized into “good or very good” (1-2) or “fair, bad or very bad” (3-5). Leisure time physical activity (LTPA) was reported on a four-graded scale and dichotomized into sedentary/low LTPA or moderate/high LTPA. At baseline, 213 individuals with IGT and 129 with IFG were detected and used for further analyses in this cross-sectional study.
Results: Individuals with IGT were found to have lower self-rated health than individuals with IFG (OR=1.62, CI: 1.01-2.60, p=0.047). There was a borderline interaction between sex and IGT/IFG considering self-rated health (p=0.055) and the difference in self-rated health was seen particularly in men when adjusted for age and BMI (OR=2.13, CI: 1.13-4.02, p=0.020). The results remained significant when also adjusting for smoking, history of CVD and lack of sleep, but became insignificant when including physical activity in the model (OR=1.8, CI: 0.91-3.58, p=0.094). Individuals with IGT reported a lower level of physical activity than those with IFG (OR=2.2, CI: 1.30-3.75, p=0.004) when adjusting for age, BMI and history of CVD. No significant differences were seen in alcohol consumption (P=0.209) or smoking (p=0.150).
Conclusion: This study shows that individuals with IGT had significantly worse self-rated health than individuals with IFG and also a less physically active lifestyle. These results indicate that physical inactivity might be an important explanatory factor behind the observed association between low self-rated health and IGT. These findings are important to consider in care-taking and treatment of patients with IGT and IFG in primary care.