Tumour necrosis factor-alpha plasma levels in elderly patients with Type 2 diabetes mellitus-observations over 2 years.

Abstract

The cytokine tumour necrosis factor-alpha (TNF-alpha) is involved in the development of obesity-linked insulin resistance. TNF-alpha plasma levels rise with increasing age and might thus also be related to metabolic control in Type 2 diabetes mellitus. We have studied the relationship of TNF-alpha plasma levels to glycaemic control in elderly patients with Type 2 diabetes over 2 years. Clinical and laboratory data of 53 patients (26 women, 27 men) with Type 2 diabetes (mean age 71.6 +/- 5.6 years) were regularly evaluated over 2 years, and the relationship to anti-diabetic treatment regimens analysed. TNF-alpha plasma level was measured by a solid-phase enzyme amplified sensitivity immunoassay. TNF-alpha plasma levels increased significantly from 16.2 +/- 9.6 pg/ml at baseline to 28.0 +/- 13.8 pg/ml after 2 years (P = 0.028). HbA1c values also increased from 6.4 +/- 1.2% to 7.7 +/- 1.6% (P = 0.046). Mean body mass index of the patients remained almost constant, while a moderate increase in the percentage of body fat (34.5 +/- 7.0% to 35.3 +/- 6.9%; P= 0.061) and in waist-hip ratio was observed (0.86 +/- 0.04 to 0.88 +/- 0.04; P= 0.052). After adjustment for covariates multivariate analysis demonstrated that TNF-alpha plasma levels are positively related to the HbA1c values of the whole study population at the baseline control and after 2 years. TNF-alpha also revealed a positive correlation to the percentage of body fat. In elderly patients with Type 2 diabetes TNF-alpha plasma levels revealed a continuous increase during an observation period of 2 years. This increase in TNF-alpha plasma levels might add another aspect to the worsening of glycaemic control in the progression of Type 2 diabetes.