Plasma insulin levels are increased by sertraline in rats under oral glucose overload

Recognition and control of depression symptoms are important to increase patient compliance with treatment and to improve the quality of life of diabetic patients. Clinical studies indicate that selective serotonin reuptake inhibitors (SSRI) are better antidepressants for diabetic patients than other drugs. However, preclinical trials have demonstrated that not all SSRI reduce plasma glucose levels. In fact, fluoxetine increases and sertraline decreases glycemia in diabetic and non-diabetic rats. In the present study we evaluated plasma insulin levels during fasting and after glucose overload after treatment with sertraline. Adult male Wistar rats were fasted and treated with saline or 30 mg/kg sertraline and submitted or not to glucose overload (N = 10). Blood was collected and plasma insulin was measured. The mean insulin levels were: fasting group: 25.9 +/- 3.86, sertraline + fasting group: 31.10 +/- 2.48, overload group: 34.1 +/- 3.40, and overload + sertraline group: 43.73 +/- 5.14 microU/ml. Insulinemia was significantly increased in the overload + sertraline group. There were no differences between the other groups. No difference in glucose/insulin ratios could be detected between groups. The overload + sertraline group was the only one in which a significant number of individuals exceeded the upper confidence limit of insulin levels. This study demonstrates that sertraline increases glucose-stimulated insulin secretion without any change in peripheral insulin sensitivity.