Improvement of cardiovascular risk factors in patients with type 2 diabetes after long-term continuous subcutaneous insulin infusion.

Background: The effects of long-term continuous subcutaneous insulin infusion (CSII) on cardiovascular risk factors such as hyperglycaemia, dyslipidaemia, and proinflammatory cytokine levels have not been assessed so far in type 2 diabetes.

Methods: We analysed the levels of HbA(1c), serum lipids, tumor necrosis factor alpha (TNF-alpha), and interleukin 6 (IL-6) at 0, 2, and 30 weeks after CSII in 15 patients with type 2 diabetes (mean age, 53.3+/-10.1 years; disease duration, 9.4+/-5.3 years) without previous history of major cardiovascular events.

Results: At week 30, CSII significantly lowered HbA(1c) by 5.0+/-0.9% compared to baseline (7.9+/-1.9%, p<0.001) and improved high-density lipoprotein cholesterol (HDLc; 1.09+/-0.16 at baseline vs 1.25+/-0.15 mmol/L at week 30; p<0.05) and low-density lipoprotein cholesterol (LDLc)/HDLc ratios (2.8+/-1.4 at baseline vs 2.2+/-0.9 at week 30; p<0.05). CSII also decreased the proportion of patients with dyslipidaemia at week 30. At baseline, TNF-alpha and IL-6 levels were up-regulated (2.65+/-4.04 and 2.82+/-1.81 pg/mL, respectively) compared to the normal control (p<0.01 and p<0.05, respectively); however, cytokine levels decreased significantly at week 30 (1.44+/-2.25 and 1.99+/-1.05 pg/mL, respectively; p=NS vs control).

Conclusions: Long-term CSII alone decreased cardiovascular risk factors in poorly controlled type 2 diabetes, suggesting that the synchronization of sufficient insulin peaks with meal ingestion and continuous pulsatile infusion of basal insulin corrects metabolic derangements.