Chronic inflammation role in the obesity-diabetes association: a case-cohort study

• Published in: Diabetology and metabolic syndrome Vol. 5; no. 1; p. 31
• Main Authors: Luft, Vivian C, Schmidt, Maria I, Pankow, James S, Couper, David, Ballantyne, Christie M, Young, J Hunter, Duncan, Bruce B
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 27-06-2013; BioMed Central
• Subjects: Complications and side effects; Diabetes; Inflammation; Insulin resistance; Kinases; Obesity; Physiological aspects; Risk factors; Studies; Type 2 diabetes; United States > US
• ISSN: 1758-5996; 1758-5996
• DOI: 10.1186/1758-5996-5-31

Chronic inflammation is related to both obesity and diabetes. Our aim was to investigate to what extent this inflammation contributes to the association between obesity and diabetes.
Using a case-cohort design, we followed 567 middle-aged individuals who developed diabetes and 554 who did not over 9 years within the ARIC Study. Weighted Cox proportional hazards analyses permitted statistical inference to the entire cohort.
Obese individuals (BMI≥30 kg/m2), compared to those with BMI<25 kg/m2, presented a large increased risk of developing diabetes (HR[obesity]=6.4, 95%CI 4.5-9.2), as did those in the highest (compared to the lowest) quartile of waist circumference (HR[waist]=8.3, 95%CI 5.6-12.3), in analyses adjusted for age, gender, ethnicity, study center, and parental history of diabetes. Notably, further adjustment for adiponectin and inflammation markers halved the magnitude of these associations (HR[obesity]=3.2, 95%CI 2.1-4.7; and HR[waist]=4.2, 95%CI 2.8-6.5). In similar modeling, attenuation obtained by adding fasting insulin, instead of these markers, was only slightly more pronounced HR[obesity]=2.7, 95%CI 1.7-4.1; and HR[waist]=3.6, 95%CI 2.3-5.8).
The marked decrease in the obesity-diabetes association after taking into account inflammation markers and adipokines indicates their major role in the pathways leading to adult onset of diabetes in obese individuals.