Diabetes, hyperglycemia, and inflammation in older individuals: the health, aging and body composition study

Abstract

Objective: The objective of this study was to assess the association of inflammation with hyperglycemia (impaired fasting glucose [IFG]/impaired glucose tolerance [IGT]) and diabetes in older individuals.

Research design and methods: Baseline data from the Health, Aging and Body Composition study included 3,075 well-functioning black and white participants, aged 70-79 years.

Results: Of the participants, 24% had diabetes and 29% had IFG/IGT at baseline. C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) levels (P < 0.001) were significantly higher among diabetic participants and those with IFG/IGT. Odds of elevated IL-6 and TNF-alpha (>75th percentile) were, respectively, 1.95 (95% CI 1.56-2.44) and 1.88 (1.51-2.35) for diabetic participants and 1.51 (1.21-1.87) and 1.14 (0.92-1.42) for those with IFG/IGT after adjustment for age, sex, race, smoking, alcohol intake, education, and study site. Odds ratios for elevated CRP were 2.90 (2.13-3.95) and 1.45 (1.03-2.04) for diabetic women and men and 1.33 (1.07-1.69) for those with IFG/IGT regardless of sex. After adjustment for obesity, fat distribution, and inflammation-related conditions, IL-6 remained significantly related to both diabetes and IFG/IGT. CRP in women and TNF-alpha in both sexes were significantly related to diabetes, respectively, whereas risk estimates for IFG/IGT were decreased by adjustment for adiposity. Among diabetic participants, higher levels of HbA(1c) were associated with higher levels of all three markers of inflammation, but only CRP remained significant after full adjustment.

Conclusions: Our findings show that dysglycemia is associated with inflammation, and this relationship, although consistent in diabetic individuals, also extends to those with IFG/IGT.