The effects of diurnal Ramadan fasting on energy expenditure and substrate oxidation in healthy men.

The study aimed to examine the effects of diurnal Ramadan fasting (RF) on substrate oxidation, energy production, blood lipids and glucose as well as body composition. Nine healthy Muslim men (fasting (FAST) group) and eight healthy non-practicing men (control (CNT) group) were assessed pre- and post-RF. FAST were additionally assessed at days 10, 20 and 30 of RF in the morning and evening. Body composition was determined by hydrodensitometry, substrate oxidation and energy production by indirect calorimetry, blood metabolic profile by biochemical analyses and energy balance by activity tracker recordings and food log analyses. A significant group×time interaction revealed that chronic RF reduced body mass and adiposity in FAST, without changing lean mass, whereas CNT subjects remained unchanged. In parallel to these findings, a significant main diurnal effect (morning v. evening) of RF on substrate oxidation (a shift towards lipid oxidation) and blood metabolic profile (a decrease in glucose and an increase in total cholesterol and TAG levels, respectively) was observed, which did not vary over the course of the Ramadan. In conclusion, although RF induces diurnal metabolic adjustments (morning v. evening), no carryover effect was observed throughout RF despite the extended daily fasting period (18·0 (sd 0·3) h) and changes in body composition.

Insulin resistance of protein anabolism accompanies that of glucose metabolism in lean, glucose-tolerant offspring of persons with type 2 diabetes.

OBJECTIVE: To test whether protein anabolic resistance is an early defect in type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS: Seven lean, normoglycemic T2D offspring (T2D-O) and eight matched participants without family history (controls; C) underwent a 3-hour hyperinsulinemic (40 mU/m2/min), euglycemic (5.5 mmol/L) and isoaminoacidemic clamp. Whole-body glucose and protein kinetics were measured with d-[3-3H]glucose and l-[l-13C]leucine, respectively. Plasma amino acids were measured by liquid chromatography-tandem mass spectrometry. RESULTS: Fasting glycemia and glucose kinetic variables did not differ between groups. Clamp decreases in glucose rate of appearance were not different, but rate of disappearance increased 29% less in T2D-O, to a significantly lower rate. Fasting leucine was higher in T2D-O, but kinetics did not differ. Clamp increases in leucine oxidation and decreases in endogenous rate of appearance (protein breakdown) were equal, but in T2D-O, non-oxidative rate of disappearance (protein synthesis) did not increase and net balance (synthesis-breakdown) did not become positive as in C. CONCLUSIONS: Resistance of whole-body protein anabolism (synthesis and net balance) accompanies resistance of glucose uptake in T2D-O. Mechanisms responsible, possible roles in the increased risk of developing diabetes, and its potential impact on long-term protein balance require definition.

Glucagon-like peptide-1 response to acarbose in elderly type 2 diabetic subjects.

The anti-hyperglycemic effect of alpha-glucosidase inhibitors (AGI) is partly attributed to their ability to stimulate the secretion of glucagon-like peptide-1 (GLP-1), a gut hormone with insulin stimulating capability. To determine if this mechanism of action contributes significantly to the therapeutic efficacy of AGI in the elderly, 10 type 2 diabetic subjects over the age of 65 years were given a standardized test meal with or without 25, 50, or 100 mg acarbose. The serum glucose, insulin, triglycerides and GLP-1 levels were measured at baseline and at 1 and 2 h postprandially. The anti-hyperglycemic effect of acarbose was maximal at 25-mg dose under these experimental conditions. Serum postprandial insulin and triglycerides levels were not significantly altered with acarbose treatment. The postprandial serum GLP-1 levels rose significantly only in two subjects and only during treatment with 100-mg acarbose. There were no significant correlations between serum GLP-1 and serum glucose or insulin levels. It is concluded that in most elderly type 2 diabetic subjects, maximal anti-hyperglycemic effects can be achieved with relatively small doses of acarbose and that GLP-1 is unlikely to contribute to the clinical efficacy of this agent in this subgroup of subjects.

A retrospective study of surgically excised phaeochromocytomas in Newfoundland, Canada.

OBJECTIVE: A retrospective study detailing the circumstances surrounding diagnosis and treatment of pheochromocytomas with the associated genetic disorders. MATERIALS AND METHODS: All patients with surgically excised pheochromocytomas in the Health Sciences Center, St. John's, Newfoundland, Canada between January 2001 and December 2010 were retrospectively analyzed to determine associated familial syndromes, age, tumor size, symptomatology, and percentage of paragangliomas and bilateral pheochromocytomas. Pathology specimen reports, adrenalectomy lists and Meditech (electronic medical record) diagnostic codes provided a comprehensive database for this study. RESULTS: Twenty-four patients were studied; familial disorder patients comprised 42% (10/24). Average age at diagnosis was 57 among the sporadic and 34 in familial disorder groups (P = 0.006). Average tumor size was 4.5 cm in the sporadic group and 3 cm in the familial disorder group (P = 0.19). All atypical cases including bilateral or extra-adrenal tumors and malignancy occurred in familial disorder patients. CONCLUSIONS: The proportion of familial disorder patients (42%) was higher in this study than would be expected, likely a result of the relatively high incidence of hereditary autosomal dominant disorders within Newfoundland. Among familial disorder patients, the average younger age at diagnosis and the smaller tumor size suggest syndromic pheochromocytomas may develop earlier, however they are more likely to be diagnosed sooner due to biochemical surveillance testing in known genetic disorder patients. We also demonstrate a relatively high incidence of surgically resected pheochromocytomas of 4.679/million/year in Newfoundland.

Growth hormone deficiency, short stature, and juvenile rheumatoid arthritis in a patient with autoimmune polyglandular syndrome type 1: case report and brief review of the literature.

Autoimmune polyglandular syndromes (APSs) include a cluster of autoimmune and nonautoimmune conditions which have been classified into subtypes. APSs type 1 is characterized by at least two of the following: chronic mucocutaneous candidiasis, chronic hypoparathyroidism, and autoimmune Addison's disease (AD). We report the chronological history of a female patient who presented with features most consistent with APS type 1, along with growth hormone deficiency and juvenile rheumatoid arthritis (JRA). In terms of her autoimmune diagnoses, she first presented with JRA at three years of age, then hypocalcemia and hypoparathyroidism at five years of age, type 1 diabetes (DM 1) at age eleven years, adrenal insufficiency at age fourteen years, recurrent mucocutaneous candidiasis as a teenager, growth hormone deficiency at age fourteen years leading to significant short stature, primary amenorrhoea, and hypogonadism, and finally alopecia at age twenty-six years. In addition to this, she has suffered other nonautoimmune medical problems including a Tetralogy of Fallot with a surgical repair at age six years. On review of the medical literature, we found no other previously reported case with this unique combination of medical problems.

Exacerbation of underlying hypothyroidism caused by proteinuria and induction of urinary thyroxine loss: case report and subsequent investigation.

OBJECTIVE: To describe a patient with excess urinary thyroxine (T4) excretion and worsening of preexisting hypothyroidism in the setting of nephrotic syndrome and to determine whether excess urinary T4 excretion is present in other patients with proteinuria. METHODS: We present data regarding the patient's initial presentation, diagnostic studies, and course of her illness. We suspected urinary T4 loss to be the cause of her presentation and analyzed her urine sample for total T4. We also analyzed differences in urinary T4 excretion in 22 patients with proteinuria and 16 control patients without proteinuria. Relevant medical literature is reviewed. RESULTS: A 44-year-old woman presented with a 3-month history of increasing fluid retention, weight gain, and fatigue. She had long-standing hypothyroidism on a stable levothyroxine dosage, 125 mcg/d. She had gained 27 kg and had developed significant edema. She had a grossly elevated thyroid-stimulating hormone level of 91 mIU/L. Her condition worsened, and a urinary protein measurement was 14.06 g/24 h-diagnostic of nephrotic syndrome. The levothyroxine dosage was increased to 225 mcg/d. Urinary total T4 concentration in a 24-hour sample was 59.0 microg/L (83.1 microg/24 h), indicating that a substantial fraction of her orally ingested T4 was lost in urine. Urinary total T4 excretion was significantly higher in patients with proteinuria (mean +/- standard deviation, 18.0 +/- 18.2 microg/L) vs control patients without proteinuria (mean, 3.8 +/- 1.8 microg/L) (P = .0014). CONCLUSION: In the patient described, urinary T4 loss due to proteinuria and nephrotic syndrome resulted in a severe exacerbation of underlying hypothyroidism.