Lifestyle modification in the management of insulin resistance states in overweight/obesity: the role of exercise training

Physical inactivity is a major contributor to overweight/obesity and associated disorders including cardiovascular diseases (CVDs), diabetes, and insulin resistance (IR). Intensive lifestyle modification (ILM) is recommended as first-line treatment for obese individuals at risk for IR. Exercise is considered to be a critical component of ILM. This narrative review discusses the role of exercise in the management of IR in overweight/obesity. PubMed and Google Scholar were searched for articles published between January 1990 and January 2019 that examined mechanisms behind the effects of exercise on IR states associated with overweight/obesity. Studies examining and/comparing effects of exercise mode, volume and/intensity on IR were also retrieved. Medical Subject Headings (MeSH) used were ‘metabolic diseases’ OR ‘chronic diseases’ AND ‘exercise’ and their related terms. Text words used in conjunction with the MeSH terms were ‘aerobic training/exercise’ OR ‘resistance training/exercise’ OR ‘high intensity interval training/exercise’, OR ‘low volume training/exercise’. Reference lists of retrieved articles were also searched for appropriate studies. Aerobic exercise training (AET) and resistance exercise training (RET) appear to produce comparable effects on obesityinduced IR states. RET, however, appears to be associated with greater improvements in glucose disposal in skeletal muscle, which is usually the primary site for IR. This is partly attributed to greater increases in key proteins involved in the insulin signalling pathway including protein content of glucose transporter 4 (GLUT-4) following RET. A study on individuals with impaired glucose tolerance (IGT) showed that RET improved glucose disposal by 23%, primarily due to a 27% increase in non-oxidative glucose metabolism, suggesting that RET may delay the manifestation of diabetes in patients with IGT. Furthermore, studies reviewed here show that components of exercise including the mode, volume and intensity of exercise training are an integral element in exercise prescription and must be recommended in accordance with the desired outcome

Characteristics and outcome of surgically treated acromegaly patients attending an endocrinology clinic at a tertiary referral centre in Durban, South Africa over a period of 10 years

Background: The mode of presentation, clinical, radiologic and laboratory characteristics of patients with acromegaly and the outcome following various modalities of treatment are not well documented in South Africa.Aim: To evaluate treatment outcome and follow-up of patients with acromegaly over a period of 10 years.Methods: The study is a retrospective record review of patients with acromegaly attending Inkosi Albert Luthuli Central Hospital, Durban, 2003–2013.Results: The study included 27 patients (16 female and 11 male) with a mean age at diagnosis of 44.2 ± 14.0 years. The mean growth hormone (GH) at diagnosis was 51.8 ± 32.6 μg/l and mean IGF-1 956.8 ± 432.9 μg/l. In 25 patients (92.5%) pituitary macroadenoma was identified; microadenoma was present in 2 (7.4%) patients. Trans-sphenoidal surgery was employed in 26 (96.3%) as the initial therapy; only 1 patient was treated medically. Adjunctive medical therapy was used in 23 (88.5%) and radiotherapy in 6 (22.2%). After a mean follow-up of 4.4 ± 3.4 years, 9 (33.3%) subjects were cured (normal age-matched and gender-matched IGF-1 and random GH < 1.0 μg/l). No deaths were recorded and post-procedural hypopituitarism developed in 22 (84.6%) patients.Conclusions: Patients with acromegaly in KwaZulu-Natal present with advanced clinical features and large pituitary adenomata. The overall cure rate is lower than reported from developed countries.Keywords: acromegaly, diagnostic criteria, medical and radiotherapy, modes of treatment (surgery

Rickets mimicker: A report of two cases of primary hyperparathyroidism in adolescence

The presentation of primary hyperparathyroidism (PHPT) in most Western countries has evolved from the classic description of ‘stones, bones, and groans’ to becoming increasingly asymptomatic as a result of more frequent serum calcium screening. However, many developing countries are still reporting predominantly symptomatic PHPT with the classic complications of skeletal disease and nephrolithiasis still being quite common. Furthermore, the exact prevalence of PHPT in children is not known but it is thought to be uncommon and the clinical presentation and outcomes in this subgroup of patients are not well described in the literature. Two cases of PHPT occurring in adolescent boys are reported. Both cases initially presented with chronic bone pain involving the lower limbs and had a long delay before the diagnosis of PHPT was confirmed. They developed progressive deformities of the lower limbs, which resembled rickets clinically. Radiological features were also suggestive of rickets. However, biochemistry confirmed parathyroid hormone mediated hypercalcaemia in both cases and after parathyroid surgery a parathyroid adenoma was confirmed histologically as the aetiology of hypercalcaemia. Therefore, PHPT occurring in adolescence may have a clinical presentation almost identical to that of rickets. All patients presenting with skeletal deformities including a rickets phenotype must have serum calcium and phosphate levels measured as part of the diagnostic workup

Characteristics and outcome of patients with pheochromocytoma at a tertiary endocrinology clinic in Durban, South Africa over 14 years

Objectives: To evaluate the characteristics and outcomes of treatment of patients with pheochromocytoma at Inkosi Albert Luthuli Central Hospital (ILACH) in Durban, South Africa over 14 years.Design: Retrospective chart review.Setting and subjects: Patients with pheochromocytoma attending the endocrinology clinic at IALCH between 2012 and 2016 were studied.Outcome measures: Clinical, biochemical and radiological data were collected at presentation, on discharge, one year and five years after surgical intervention; tumour characteristics, histopathological features and surgical outcome were also assessed.Results: The analysis included 35 patients (mean age 33.2 ± 15.7 years; 60% female). Headache (68.6%), palpitation (60%) and sweating (57.6%) were the three most common presenting symptoms; hypertension was the predominant clinical finding (85.7%). Most pheochromocytomas were sporadic (82.9%), adrenal gland tumours (68.6%) and benign (77.1%); of eight patients with malignant tumours, two were familial. Adrenalectomy was undertaken in the majority (n = 34; 97.1%); 55.2% were large tumours. The use of adjunctive radiotherapy (n = 4; 11.4%) and chemotherapy (n = 1; 2.9%) was low. There was low overall mortality (5.7%), but 57.6% developed intraoperative hypotension. At one year postoperatively, 80% (n = 28) of patients were defined as cure, biochemically in 23 (82.1%) and with radiology in five (17.9%).Conclusions: Most patients presenting to IALCH had large intra-abdominal tumours with high cure rate, low mortality but a high rate of perioperative complications. Late presentation and large tumour size was a feature.Keywords: pheochromocytoma , South Africa, surgical outcom

Prevalence of low serum testosterone levels among men with type 2 diabetes mellitus attending two outpatient diabetes clinics in KwaZulu-Natal Province, South Africa

Background. The reported prevalence of low testosterone among men with type 2 diabetes mellitus (T2DM) is high. However, there is a dearth of information on the prevalence of androgen deficiency symptoms and low serum testosterone levels in men with T2DM from sub-Saharan Africa. Scanty data are available from Nigeria, Ghana and South Africa (SA).Objectives. To determine the prevalence of low serum testosterone and associated risk factors and the prevalence of androgen deficiency symptoms in men with T2DM.Methods. In a cross-sectional observational study, androgen deficiency symptoms in men with T2DM attending two outpatient diabetes clinics in Durban, KwaZulu-Natal Province, SA, were assessed using the Ageing Males’ Symptoms Scale (AMS) questionnaire and direct enquiry. Serum total testosterone (TT), sex hormone-binding globulin (SHBG), luteinising hormone (LH), fructosamine, serum lipids and glycated haemoglobin (HbA1c) were measured and free testosterone (FT) was calculated. TT, SHBG and FT levels were measured in control subjects with no history of diabetes.Results. There were 148 men with T2DM in the study group and 50 control subjects in the control group. In the study group, the majority were black Africans (58.8%); Indians (39.2%) and whites (2.0%) constituted the remainder. The mean (standard deviation (SD)) age was 57.5 (11.2) years, the mean duration of diabetes 11.4 (8.9) years and the mean HbA1c 8.6% (1.9%). Of the study group, 85.8% had metabolic syndrome. Mean TT, SHBG and FT and median LH (interquartile range) in the study group were within normal ranges. However, mean (SD) serum TT and FT were lower in the study group than in the control subjects (14.5 (5.8) v. 18.8 (7.2) nmol/L; p<0.001 and 265.9 (90.4) v. 351.7 (127.3) pmol/L; p<0.001, respectively). The prevalence of low serum total testosterone (LSTT) and low serum free testosterone (LSFT) in the study group was 35.8% and 16.2%, respectively. The prevalence of androgen deficiency symptoms using the AMS questionnaire was 74.5% and correlated poorly with LSTT or LSFT. In multivariate analysis, LSFT was significantly associated with age (odds ratio (OR) 1.05, 95% confidence interval (CI) 1.02 - 1.218; p=0.043) and waist circumference (WC) (OR 1.033, 95% CI 0.999 - 1.068; p=0.059). LSTT was associated with body mass index (BMI) only (OR 1.138, 95% CI 1.063 - 1.218; p<0.0001). TT correlated inversely with BMI, WC and the number of metabolic syndrome criteria. FT correlated inversely with BMI, WC and WHR.Conclusions. There was a high prevalence of LSTT, LSFT and androgen deficiency symptoms in this study. Serum TT and FT were lower in men with T2DM than in control subjects. Risk factors associated with LSFT or LSTT included higher BMI and WC and older age. The AMS score was a poor predictor of low testosterone. More research is required locally before any screening policy can be recommended.

Microvascular complications in South African patients with long duration diabetes mellitus

Objective. To determine the prevalence of microvascular complications in South African black and Indian patients with long-duration diabetes mellitus (DM).Design. A retrospective analysis was undertaken of clinical records of 219 OM patients (132 black, 87 Indian) with longduration OM (over 10 years) attending a diabetes clinic in Durban. Data recorded on each subject included demographic details (age, gender, ethnic group, type of diabetes, age of onset and duration of diabetes), presence of retinopathy, markers of nephropathy and biochemical variables. The prevalence of complications and the clinical and biochemical parameters were evaluated for type 1 and type 2 diabetes and for each ethnic group.Results. Of the 219 patients, 47 had type 1 OM (36 blacks, 11 Indians) and 172 were classified as type 2 OM (96 blacks, 76 Indians). The mean age of onset of OM wa later in blacks than Indians, both for type 1 (P < 0.05) and type 2 OM (P < 0.01). In patients with type 1 OM, the prevalence of retinopathy was 53.2% (blacks 55.6%, Indians 45.5%), persistent proteinuria was found in 23.4% (blacks 25%, Indians 18.2%) and hypertension in 34%. 0 ethnic difference was found except for the prevalence of hyperten ion which was higher in blacks than Indians (41.7% v. 9.1%, P < 0.5). Onset of retinopathy from time of diabetes diagno is occurred earlier in blacks than Indians (13.0 ± 4.6 yrs v. 18.0 ± 4.6 yrs, P < 0.05). For the type 2 DM group, retinopathy was found in 64.5% (black v. Indian 68.8 v. 59.2%) and per istent proteinuria in 25% (black v. Indian 30.2 v. 1 .4%). Hypertension wa observed in 68% and wa more prevalent in blacks (84.4 v. 47.,*%, P < 0.01) There was an earlier onset of retinopathy (P < 0,05) and hypertension (P < 0.01) from time of diabetes diagnosis in blacks than Indians. In the type 1 OM group retinopathy was a sociated with a ignificantly longer duration of diabetes (P < 0.05) and higher glycated haemoglobin (HbA1) (P < 0.05). For type 2 DM subjects there was a significant association between retinopathy and longer duration of diabetes (P < 0.05) and higher systolic blood pressure (P < 0.05).Conclusion. 1his study has shown that there is a high prevalence of microvascular complications in South African patients with long-duration diabetes mellitus

Diabetes and Other Disorders of Glycemia in a Rural South African Community: Prevalence and associated risk factors

OBJECTIVE—The purpose of this study was to determine the prevalence of diabetes, impaired glucose tolerance (IGT), impaired fasting glycemia (IFG), and associated risk factors in a rural South African black community

Cushing's syndrome caused by ectopic ACTH secretion from pulmonary tumourlets

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