Abstract
Weight loss intervention is the principal non-pharmacological method for prevention
and treatment of type 2 diabetes. However, little is known whether it influences insulin
sensitivity directly or via its anti-inflammatory effect. The aim of this study was
to assess the independent role of changes in inflammation status and weight loss on
insulin sensitivity in this population.
Overweight and obese nondiabetic participants without co-morbidities underwent a one-year
weight loss intervention focused on caloric restriction and behavioral support. Markers
of inflammation, body composition, anthropometric parameters, and insulin sensitivity
were recorded at baseline, 6, and 12 months. Insulin sensitivity was assessed with
frequently sampled intravenous glucose tolerance test and Minimal Model. Twenty-eight
participants (F: 15, M: 13, age 39±5 years, BMI 33.2±4.6 kg/m2) completed the study, achieving 9.4±6.9% weight loss, which was predominantly fat
mass (7.7±5.6 kg, p<0.0001). Dietary intervention resulted in significant decrease
in leptin, leptin-to-adiponectin ratio, hs-CRP, and IL-6 (all p<0.02), and improvement
in HOMA-IR and Insulin Sensitivity Index (SI) (both p<0.001). In response to weight
loss IL-1β, IL-2, leptin, and resistin were significantly associated with insulin,
sensitivity, whereas sICAM-1 had only marginal additive effect. Moderate weight loss
in otherwise healthy overweight and obese individuals resulted in an improvement in
insulin sensitivity and in the overall inflammation state; the latter played only
a minimal independent role in modulating insulin sensitivity.
Key words
insulin sensitivity - inflammation - obesity - weight loss - leptin