A polymorphic marker in the leptin gene associated with Japanese morbid obesity.

The prevaleance of morbid obesity (body mass index of 35.0 or greater) is low in Japan (0.2-0.3%), and little systematic investigation of its cause in this population has been carried out. Leptin plays a central role in regulation of body weight; mice deficient in leptin develop marked obesity. We sought mutations in the leptin gene in 53 morbidly obese Japanese (maximum body mass index 35-60) including 46 with type 2 diabetes. Direct DNA sequencing was performed following polymerase chain reaction amplification. Apart from a silent mutation at codon 25 (CAA/CAG, glutamine) detected in eight subjects, no mutations were detected. We found a significantly higher prevalence of the variant leptin 25CAG allele among the 53 obese subjects (0.085) studied than in 132 nonobese control subjects (0.011, P<0.001). In Japanese populations mutations in the protein coding sequence of the leptin gene are unlikely to be a major cause of morbid obesity. However, the leptin 25CAG allele may be linked to morbid obesity in this population. Specifically, genetic variation located near the leptin gene may be involved in pathogenesis. The leptin polymorphism 25CAG appears to be a new genetic marker for obesity susceptibility, at least in Japanese.

Clinical characteristics in non-insulin-dependent diabetic patients with long duration in Japan--relation to risk factors for vascular complications.

In this study, we evaluated the control state of body weight, blood pressure, and blood glucose during the recent 10 years in 82 patients of non-insulin-dependent diabetes mellitus (NIDDM) who had long duration of diabetes for 20-25 years without ischemic heart disease (IHD) and diabetic nephropathy (Neph). The patients without either IHD or Neph showed significantly lower incidences of obese (11 vs. 40%, p < 0.05), hypertensive (0 vs. 20%, p < 0.05) and poor glycemic control state (7 vs. 27%, p < 0.05) for 10 years than the patients with IHD alone, and showed significantly lower incidences of hypertensive (0 vs. 20%, p < 0.05) and poor glycemic control state (7 vs. 33%, p < 0.01) than the patients with Neph alone. The control state of body weight was similar between the patients without either IHD or Neph and with Neph alone. In addition, the patients without either IHD or Neph showed significantly lower incidences of obese (11 vs. 56%, p < 0.01) and hypertensive control state (0 vs. 40%, p < 0.01) for 10 years than the patients with both IHD and Neph. The control state of blood glucose was similar between the two groups. These results suggest that for long survival of NIDDM patients without development or progression of IHD and Neph, non-obese and non-hypertensive state as well as good glycemic control should be maintained for long time.

Pheochromocytoma with multiple islet cell carcinoma.

We reported a rare case of a 17-year-old female with pheochromocytoma associated with multiple islet cell carcinoma. Pheochromocytoma was identified in the right adrenal gland. Multiple pancreas tumours were demonstrated unpredictably in the diagnostic imaging of the pheochromocytoma. No other endocrinological neoplasm was observed in the pituitary, thyroid and parathyroid gland. The patient underwent right adrenalectomy and total pancreatectomy. Pheochromocytoma was benign, however, pancreas tumours were non-functioning islet cell tumours and histologically malignant. This combination is assumed to represent a mixed form of multiple endocrine neoplasia (MEN) 1 and MEN 2.