Circulating concentrations of adiponectin, an adipocyte-derived protein, are increased by thiazolidinediones and by weight reduction, accompanied with improvement in insulin sensitivity. The effect of exercise training, another therapy to increase insulin sensitivity (SI), on adiponectinemia is currently unclear. The present study was undertaken to clarify whether exercise training-induced increase in SI is related to changes in adiponectinemia in healthy men. Twelve healthy non-obese men underwent ergometer training at lactate threshold (LT) intensity for 60 min/day for 5 days/week for 6 weeks. An insulin-modified intravenous glucose tolerance test was performed before and at 16 h and 1 week after the last training session to determine SI using a minimal-model approach. Serum levels of adiponectin were determined at the same time. After the exercise training, VO2max and LT were significantly increased by 7.2% and 22.3% (P<0.01), while BMI and body fat mass remained unchanged. SI was significantly increased at 16 h after the last training session (from 7.0 +/- 3.1 to 9.6 +/- 3.6 [x 10(-4) x (microU/ml)(-1) x min(-1)], P<0.01), but returned toward the basal levels at 1 week after the cessation of the training. Serum adiponectin concentrations before the training (20.9 +/- 7.4 microg/ml) were positively correlated with SI. The concentrations were slightly but significantly decreased at 16 h (17.2 +/- 6.6 microg/ml, P<0.05), and returned to the basal values at 1 week after the training. From these results, it can be concluded that exercise training-induced increase in SI is not dependent on the increase in adiponectinemia in healthy men.
Objective: Hyponatremia occurs not infrequently in hypopituitarism. Arginine vasopressin (AVP)-induced impaired water excretion is found in patients with hypopituitarism and experimental models of glucocorticoid deficiency. Design: The present study was undertaken to determine whether augmented release of AVP is involved in the development of hyponatremia in elderly subjects with secondary adrenal insufficiency. Methods: Forty patients with ACTH-deficient, secondary adrenal insufficiency were examined. They were divided into three groups according to the age at which diagnosis was ascertained (group A , 20 years, group B 20-64 years, and group C $ 65 years). Results: Hyponatremia was more manifest in the elderly group than in the other two groups, serum sodium (Na) levels being 124.7 mmol/l in the elderly group, a value significantly less than 141.5 and 133.5 mmol/l in groups A and B. Plasma AVP levels seemed likely to be high compared with the respective hypo-osmolality in plasma in the elderly group, as plasma AVP levels were 1.7 pmol/l despite a mean plasma osmolality of 259 mmol/kg. Such an alteration was less clear in group B and was not found in group A. Therefore, elevation of plasma AVP was apparent in the elderly patients. Hydrocortisone replacement promptly normalized serum Na levels from 125 to 142 mmol/l ðP , 0:01Þ and reduced plasma AVP levels from 1.7 to 0.9 pmol/l ðP , 0:05Þ; which were comparable to the respective plasma osmolality in the elderly patients. Conclusion: These results indicate that non-suppressible release of AVP is crucially involved in the impaired water excretion and hyponatremia seen in elderly patients with secondary adrenal insufficiency compared with the younger patients, and that exaggerated release of AVP becomes manifest as the subjects grow older.
A lthough the number of children and youth with type 2 diabetes is increasing, a clear case definition that describes children with type 2 diabetes at presentation remains elusive. Most initial diagnoses are decided on the clinical picture at presentation (1). Characteristics and risk factors have been outlined in several review and clinical articles (2-4). The purpose of this study was to describe the characteristics of youth presenting for an initial visit to the outpatient clinic of a large tertiary children's care center and diagnosed with type 2 diabetes.For this retrospective study, data were abstracted from a consecutive sample of 98 patients' medical records at Texas Children's Hospital starting 1 January 1998 and ending 31 October 2001. The sample's mean age at diagnosis was 13.6 years (SD 2.33; range 8.7-18.4 years). Fifty-one percent of the children were female and 49% were male (female: male ratio 1:1). For 43% race/ethnicity was not specified; the remaining participants were 28.6% African American, 22.4% Hispanic, 3.1% non-Hispanic white, and 3.1% Asian. Of those for whom data were available, a maternal history of type 2 diabetes was reported by 32.7% (18/55) and an unspecified type of diabetes by 12.7% (7/55). Twenty-seven percent (13/47) reported a father with type 2 diabetes and 21% (10/47) an unspecified type of diabetes.Mean BMI was 34.67 kg/m 2 (SD 6.91). Ninety-three percent had a BMI Ն95th percentile. All but three of the individuals had BMIs Ն85th percentile. Of those for whom data were recorded, acanthosis nigricans was identified in 94% (48/51). A Tanner stage of 3, 4, or 5 was identified in 73.2% (49/67).Blood pressure readings indicated that 49.4% (41/83) had a systolic (SBP) and 10.8% (9/83) a diastolic (DBP) Ն95th percentile for age, sex, and height (n ϭ 83). Fifty-five percent (46/83) had SBP and 19.3% (16/83) DBP readings Ն90th percentile for blood pressure. Of 72 pulse rates recorded, 2.6% were Ն95th percentile for age. Average HbA 1c was 10.38 (SD 3.52) (n ϭ 95).Of those who had symptoms documented in the medical record, 83.6% (56/ 67) reported polyuria, 83.9% (52/62) polydipsia , and 61% (36/59) polyphagia. Seventy-five percent reported both polyuria and polydipsia (46/61). Of the cases available, 46.2% (24/52) reported all three of the polys at initial presentation, 46.8% (29/62) had weight loss, and 62.5% (30/48) had ketones. Of those for whom islet cell antibody data were recorded (50/98), 49 had JDF units Ͻ5. Fifty-three percent were started on insulin, 46.3% on oral agents, and 13.7% on both insulin and oral agent (n ϭ 96). Initial mean insulin dose was 0.6 units/kg.Our sample is similar to those described in previous reports except for a more even ratio of female to male subjects, a greater percent with elevated SBP and/or DBP, and more individuals reporting weight loss. We are the first to report blood pressure by the 95th and 90th percentiles and the first to report pulse rate. These data contribute to the growing body of clinical evidence defining the characteristics of ...
Abstract. ACTH-independent macronodular adrenal hyperplasia (AIMAH) is a rare cause of Cushing's syndrome. Bilateral adrenalectomy is considered to be a standard therapy for AIMAH, although lifetime replacement of glucocorticoids is necessary after the procedure. This paper describes a subject with AIMAH who underwent unilateral adrenalectomy of the predominantly enlarged gland and subsequently displayed an improvement in insulin resistance and diabetes mellitus, the cardinal symptoms before the operation, concomitant with alleviation of abnormal cortisol secretion. The patient was a 61-year-old man with a body mass index of 25.6 kg/m 2 . He was diagnosed as having diabetes mellitus, hypertension, and hyperlipidemia at 50 years of age. Eight years after diagnosis, bilateral enlargement of the adrenal glands was revealed by chance upon computed tomography of the abdomen. Typical manifestations of Cushing's syndrome were not demonstrated. Basal levels of serum and urinary cortisol had not increased, although the serum cortisol level displayed no circadian rhythm and no response to the administration of dexamethasone. Despite sulfonylurea treatment, the patient's HbA 1C level was as high as 7.6% (normal range 4.3-5.8%). Fasting insulin concentration was increased to 42.6 mU/ml, and the homeostasis model insulin resistance index (HOMA-R) was calculated to be 15.5 (with a normal range of less than 2.5), indicating severe insulin resistance. Unilateral adrenalectomy of the predominantly enlarged gland revealed that the resected gland consisted of multiple nodules of various sizes. Based on endocrinological, radiological, and pathological findings, a diagnosis of AIMAH was made. Ten months after the unilateral adrenalectomy, cortisol circadian rhythms were restored, and serum cortisol concentration was suppressed in response to the administration of low doses of dexamethasone, suggesting an improvement in the cortisol secretory pattern. Levels of HbA 1C , fasting insulin, and HOMA-R decreased to 5.7%, 12.7mU/ml, and 2.2, respectively. An improvement in hyperlipidemia was also observed. Insulin resistance and glucose intolerance are recognized as features of mild hypercortisolism. In the present case, unilateral adrenalectomy was effective in ameliorating insulin resistance and improving glycemic control. Unilateral adrenalectomy might be an alternative therapy for improvement of glucose and lipid metabolism in subjects with AIMAH.
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