VITAMIN DEFICIENCY AND INSULIN RESISTANCE IN NONDIABETIC OBESE PATIENTS.

OBJECTIVE: Obese people may have nutritional deficiencies, although they are exposed to excessive food intake. We aim to assess relationship of vitamin D, B12, and folic acid levels and dietary vitamin intake and insulin resistance in obese people. DESIGN: This case-control study was performed at the obesity outpatient clinics between March 2014 and April 2015. SUBJECTS AND METHODS: We included 304 non-diabetic obese subjects in patient group and 150 normal weight individuals in control group. Patients were questioned in detail about their food intake. RESULTS: Mean age of obese patients was 37.3±10.1 years, the mean duration of obesity was 7.9±5.4 years, and the percentage of female patients was 65.8%. Mean vitamin D, B12, and folic acid levels were significantly lower in patients than in controls. Vitamin D deficiency (<20 ng/mL) in 69.7%, vitamin B12 deficiency (<200 pg/mL) in 13.5%, and folic acid deficiency (<4 ng/mL) was found in 14.2% of the patients. BMI negatively correlated with vitamin D, B12, and folic acid levels. B12 levels negatively correlated with duration of obesity. Insulin resistance was found in 55.9% of patients and HOMA-IR levels negatively correlated with vitamin D and B12 levels. While dietary vitamin D and folic acid intakes were inadequate in all of patients, only 28.3% of patients had inadequate vitamin B12 intake. There was no relation between vitamin levels and dietary vitamin intakes. CONCLUSIONS: The study reveals that vitamin D, B12, and folic acid levels were low and poor vitamin D and B12 status were associated with insulin resistance in nondiabetic obese patients.

Effects of rosiglitazone on plasma brain natriuretic peptide levels and myocardial performance index in patients with type 2 diabetes mellitus.

Thiazolidinediones (TZD) have become a powerful tool for lowering insulin resistance. The problem of cardiovascular adverse events including fluid retention and risk of heart failure should be well known and recognised. We aimed to evaluate the long-term effects of rosiglitazone on cardiac function and fluid dynamics. Forty-six type 2 diabetic patients were randomised to treatment with rosiglitazone or metformin or to a control group. There are no significant differences between the groups in the duration of diabetes, HbA1c, plasma brain natriuretic peptide (BNP) levels, body mass index and myocardial performance indexes (MPIs) before the treatment. After three and six months all these parameters were repeated. Rosiglitazone increased plasma BNP levels and worsened MPIs 3 months after the start of treatment. Also left ventricular end-systolic volume increased and weight gain was observed. But these results were statistically non-significant (all p>0.05). When we continued rosiglitazone treatment to six months the increase in BNP levels became soft and statistically significant improvements were seen in MPIs (p<0.01). Also left ventricular end-systolic volume decreased significantly (p=0.004) and weight gain was stopped. In patients with type 2 diabetes, TZD treatment might have slight adverse effects on ventricular contractility and fluid dynamics at the beginning of the therapy. However, these changes seem to stabilise in the long term.

Polycythemia as the first manifestation of Cushing's disease.

A 39-yr-old man presented to our hospital with unexplained erythrocytosis and hypertension. His follow-up for erythrocytosis had begun 2 yr earlier in another hospital and he had been diagnosed with polycythemia rubra vera. On admission to our hospital he was hypertensive (165/95 mmHg) and, except for the presence of moon-like face and facial plethora, his physical examination was normal. His hemoglobin concentration was 19.2 g/dl, and hematocrit was 58.9% with an increased red blood cell mass of 58 ml/kg as measured by radioisotope (Cr51). Blood film, other hematological indices except for elevated leukocyte alkaline phosphatase score, arterial gas analysis, and examination of aspirated bone marrow were all normal. An abdominal ultrasonography showed no evidence of splenomegaly. A diagnosis of probable secondary erythrocytosis was made. Early-morning serum cortisol and 24-h urinary free cortisol concentration as well as serum ACTH were high. Serum cortisol was not suppressed by low-dose dexamethasone, but suppressed by high-dose dexamethasone. Pituitary magnetic resonance imaging showed no lesion. After inferior petrosal sinus sampling suggesting right-central ACTH secretion, the patient underwent transnasal-transsphenoidal pituitary adenomectomy. Both hypercortisolemia and erythrocytosis regressed completely after the adenomectomy. After the operation, the patient's hemoglobin concentration and hematocrit decreased steadily, and 1 month post-adenomectomy his hemoglobin is 14.9 g/dl and hematocrit 44.8%. Thus, Cushing's syndrome should be a routine part of evaluation of unexplained polycythemia.