Aims: Studies on statins and insulin-sensitivity in T2DM are highly controversial. We aimed to evaluate the effect of RSV in type-2 diabetic people and whether its action may be phenotype-dependent, i.e. triglyceride (TG)-related (study approved by the local Ethical Committee).
Methods: 48 type-2 diabetic pts (22 M:26 F), in a poor glycaemic control with oral agents, insulin or a combination therapy (unchanged over the study), were given RSV 10 mg for 12 weeks and stratified in 2 groups (23:25) by fasting TG-levels (<150 and 150400 mg/dl), matched for age (59.7±9.8 vs 60.0±10.2 years), BMI (29.8±4.9 vs 29.9±5.5 kg/mq), waist (103.9±10.8 vs 105.7±11.1 cm), HbA1c (8.3±1.0 vs 8.5±1.2%), total cholesterol (TC) (245.8±33.6 vs 264.7±26.1 mg/dl), LDL-C (167.2±31.2 vs 176.6±35.0), HDL-C (45.7±11.6 vs 44.0±14.4), and Apo-B (152.4±34.8 vs 170.2±28.1). Baseline- and 12-wk samples were taken for TC, LDL-C, HDL-C, TG, Apo-B, HbA1c, fasting plasma glucose and insulin. Homeostasis Model Assessment for Insulin-Resistance (HOMA-IR) was calculated, baseline score being higher in the 2nd group (4.68±1.0 vs 6.32±1.5 P<0.05).
Results: In both groups RSV lowered LDL-C (−47.2 vs −45.8%) and Apo-B (−40.7 vs −39.6%) significantly and to a similar extent. HDL-C was significantly increased (+5.3 vs +4.4%) irrespective of changes in TG levels, mostly affected by RSV in the 2nd group: 133.5±47.9 (−17.2%) vs 250.5±60.1 (−25.9%) P<0.001. HOMA-IR correlated with TG (r=0.21) and was significantly decreased by RSV-treatment in hyper-TG-group (3.35±0.9 vs 6.32±1.5 P<0.001), as far as HbA1c showed a slight but significant improvement (−0.7% P<0.05), while no change was detected in HOMA-score or in HbA1c level in normo-TG-one, BMI and waist being not modified in both.
Conclusions: Perturbations in large-VLDL- and TG-metabolism generate an atherogenic lipid profile in T2DM and are closely linked with insulin-resistance. So in our data RSV improves HOMA-IR and HbA1c in hyper-TG type-2 diabetic pts by lowering TG-levels and seems to have both phenotype-independent and dependent (TG-related) actions.