Hyperinsulinemic hypoglycemia associated with ectopic Cushing's syndrome due to a pancreatic endocrine tumor in a Type 2 diabetes mellitus patient: clinical implications of a rare association.

BACKGROUND: The coexistence of insulin and ACTH hypersecretion in the same patient is extremely rare. A diabetic patient with a pancreatic endocrine tumor (PET) co-secreting insulin and ACTH is even rarer and has never been described. The combination of these two endocrine syndromes results in a peculiar clinical picture. AIM: To determine the cause of glycemic variations in a patient with previously stable diabetes mellitus. SUBJECTS AND METHODS: This is a clinical case report from the Endocrinology Unit of Aosta Hospital and Internal Medicine and Surgical Unit of Verona University. A 69-yr-old diabetic patient was hospitalized for recurrent severe hypoglycemic events persistent after withdrawal of anti-diabetic drugs. The causes of hypoglycemia and subsequent resumption of hyperglycemia were investigated. RESULTS: An insulin-secreting PET was diagnosed. Diazoxide and octreotide therapy initially was able to control hypoglycemic symptoms, then, a Cushing's syndrome occurred resulting in worsening of diabetes control. ACTH was found to be released by the PET previously diagnosed as an insulin-secreting tumor. The tumor was removed and the histology was consistent with a well differentiated endocrine carcinoma. After surgery, adrenal function was normal and insulin therapy was again necessary to control diabetes. CONCLUSIONS: A single PET may be responsible for both a hyperinsulinemic and a Cushing's syndrome. When this rare association occurs, each of the two syndromes may affect the other resulting in a peculiar clinical course. Finally, an insulin-secreting PET has to be kept in mind as a rare cause of hypoglycemia in diabetic patients.

Ankle brachial pressure index usefulness as predictor factor for coronary heart disease in diabetic patients.

Ankle brachial pressure index (ABPI) is a non-invasive marker of atherosclerosis, helpful to identify subjects at high-risk for coronary heart disease (CHD) among large populations with cardiovascular disease (CVD) risk factors. The diagnostic role of ABPI has been also recognized in patients with diabetes. In the present study, the role of an ABPI score < 0.90 in predicting CHD has been evaluated in a large series of patients with Type 2 diabetes mellitus and compared to other known CVD risk factors. Nine hundred and sixty-nine (mean age was 66.1 yr) consecutive patients with Type 2 diabetes mellitus were evaluated. The patients were followed-up for 18.3+/-5.2 months (range 12- 24) and all events of CHD, defined as myocardial infarction, unstable and resting angina or coronary atherosclerosis at the instrumental investigation (at the coronary angiography and/or perfusion stress testing) were recorded. A rate of 17.5% of CHD events were recorded in diabetic population during the follow-up period. The relative risk of CHD was significantly increased for male patients [odds ratio (OR): 1.6; 95% confidence interval (CI): 1.1-2.2], patients with age > or = 66 yr (OR: 1.8; 95% CI: 1.3-2.5), body mass index (BMI) > 30 (OR: 1.5; 95% CI: 1.1-2.1), waist circumference > 88 cm for females and 102 cm for males (OR: 1.5; 95% CI: 1.0-2.1), proteinuria > or = 30 microg per min (OR: 1.6; 95% CI: 1.1-2.3), LDL-cholesterol > or = 100 mg/dl (OR: 2.1; 95% CI: 1.5-3.0), glycated hemoglobin > 7% (OR: 1.6; 95% CI: 1.1-2.3), insulin therapy (OR: 1.9; 95% CI: 1.3-2.9), and ABPI < 0.90 (OR: 3.7; 95% CI: 2.2- 6.2). BMI was higher in patients with ABPI < 0.90 than in those with ABPI > or = 0.90 (p<0.05). At the multivariate analysis, ABPI < 0.90 was the best factor independently associated with CHD (p<0.001). APBI < 0.90 is strongly associated to CHD in Type 2 diabetic patients. We recommend to use ABPI in diabetic patients and to carefully monitor diabetic subjects with an ABPI lower than 0.90.

Pharmacokinetics of ofloxacin in elderly patients and in healthy young subjects.

The pharmacokinetics of ofloxacin, a fluoroquinolone widely used in the treatment of bacterial infections, may be different according to age, owing to the biological differences that exist between an elderly organism and a young subject, especially as regards the renal and the hepatic function. In our study the pharmacokinetics of ofloxacin in 12 elderly patients was found to be different from those of 12 healthy young volunteers. The elimination half-life (t1/2) was slightly shorter in the young subjects than in the elderly: 6.2 (0.9)h against 8.5(1.2)h respectively. The oral total clearance was lower in the geriatric patients compared to the young healthy volunteers: 83.3(16.6) ml/min in the first group, and 23.3(33.3) ml/min in the second group. AUC and peak plasma concentration in elderly exceeded those noted in young healthy volunteers. The results of this study suggest that, compared with younger subjects, older patients experience delayed elimination of ofloxacin. It would be reasonable, from a pharmacokinetic point of view, to limit the dose of ofloxacin in patients more than 75 years old, at least to one half of that given to younger patients.