Study of nateglinide in Japan: Long-term treatment of patients with type 2 diabetes

Nateglinide is an oral antidiabetic medication that acts through rapid, short-term stimulation of insulin production. This study undertook to identify the nature of any adverse effects of nateglinide and to assess its clinical efficacy in long-term use in clinical practice. Patients (n=1014) were recruited from centers in Japan and were followed over a 15-month treatment period. Pretreatment and post-treatment values were obtained for fasting blood glucose, postprandial blood glucose, hemoglobin A1c (HbA1c), triglycerides, and total cholesterol. All adverse reactions were noted, along with standard laboratory blood variables. The efficacy value was rated as 78.76% by the treating physicians; this was indicated by a postprandial glucose decrease of 53.2 mg/dL (from 223.8±61.1 mg/dL to 170.6±40.7 mg/dL), a fasting glucose decrease of 9.3 mg/dL (from 155.1 ± 40.0 mg/dL to 145.4±35.1 mg/dL), and an HbA1c decrease of 0.68% (from 7.51± 1.36% to 6.83±1.09%). In patients previously treated with sulfonylurea, a decrease in HbA1c was not observed. Changes in HbA1c had no association with age, body mass index (BMI), duration of diabetes, or concomitant disease. No change in BMI was noted after 15 months of nateglinide treatment. Adverse reactions occurred at an incidence of 10.07% (100/993 cases), with hypoglycemic symptoms being the most prevalent (1.91%). Adverse reactions were sometimes associated with extant renal dysfunction, a condition about which the physician had to be aware. No problems such as increased incidences of adverse reactions or deterioration in severity were detected in this long-term study. This study showed the efficacy and safety of long-term treatment with nateglinide of patients with diabetes from various backgrounds.