Bone Material Strength Index as Measured by Impact Microindentation is Low in Patients with Primary Hyperparathyroidism.

CONTEXT: In primary hyperparathyroidism (PHPT) bone mineral density (BMD) is typically decreased in cortical bone and relatively preserved in trabecular bone. An increased fracture rate is observed however not only at peripheral sites but also at the spine, and fractures occur at higher BMD values than expected. We hypothesized that components of bone quality other than BMD are affected in PHPT as well. OBJECTIVE: To evaluate bone material properties using impact microindentation (IMI) in PHPT patients. METHODS: In this cross-sectional study, the Bone Material Strength index (BMSi) was measured by IMI at the midshaft of the tibia in 37 patients with PHPT (28 women), 11 of whom had prevalent fragility fractures, and 37 euparathyroid controls (28 women) matched for age, gender, and fragility fracture status. RESULTS: Mean age of PHPT patients and controls was 61.8 ±â€…13.3 and 61.0 ±â€…11.8 years, respectively, P = .77. Calcium and PTH levels were significantly higher in PHPT patients but BMD at the lumbar spine (0.92 ±â€…0.15 vs 0.89 ±â€…0.11, P = .37) and the femoral neck (0.70 ±â€…0.11 vs 0.67 ±â€…0.07, P = .15) were comparable between groups. BMSi however was significantly lower in PHPT patients than in controls (78.2 ±â€…5.7 vs 82.8 ±â€…4.5, P < .001). In addition, BMSi was significantly lower in 11 PHPT patients with fragility fractures than in the 26 PHPT patients without fragility fractures (74.7 ±â€…6.0 vs 79.6 ±â€…5.0, P = .015). CONCLUSION: Our data indicate that bone material properties are altered in PHPT patients and most affected in those with prevalent fractures. IMI might be a valuable additional tool in the evaluation of bone fragility in patients with PHPT.

Proteomic analysis in type 2 diabetes patients before and after a very low calorie diet reveals potential disease state and intervention specific biomarkers.

UNLABELLED: Very low calorie diets (VLCD) with and without exercise programs lead to major metabolic improvements in obese type 2 diabetes patients. The mechanisms underlying these improvements have so far not been elucidated fully. To further investigate the mechanisms of a VLCD with or without exercise and to uncover possible biomarkers associated with these interventions, blood samples were collected from 27 obese type 2 diabetes patients before and after a 16-week VLCD (Modifast ∼ 450 kcal/day). Thirteen of these patients followed an exercise program in addition to the VCLD. Plasma was obtained from 27 lean and 27 obese controls as well. Proteomic analysis was performed using mass spectrometry (MS) and targeted multiple reaction monitoring (MRM) and a large scale isobaric tags for relative and absolute quantitation (iTRAQ) approach. After the 16-week VLCD, there was a significant decrease in body weight and HbA1c in all patients, without differences between the two intervention groups. Targeted MRM analysis revealed differences in several proteins, which could be divided in diabetes-associated (fibrinogen, transthyretin), obesity-associated (complement C3), and diet-associated markers (apolipoproteins, especially apolipoprotein A-IV). To further investigate the effects of exercise, large scale iTRAQ analysis was performed. However, no proteins were found showing an exercise effect. Thus, in this study, specific proteins were found to be differentially expressed in type 2 diabetes patients versus controls and before and after a VLCD. These proteins are potential disease state and intervention specific biomarkers. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN76920690.

Effects of bariatric surgery on pericardial ectopic fat depositions and cardiovascular function.

OBJECTIVE: Cardiac ectopic fat depositions are thought to play a role in the pathogenesis of cardiovascular disease (CVD), the main cause of death in patients with type 2 diabetes. Diet-induced weight loss results in a decrease in cardiac ectopic fat stores, however if this is the same for surgically induced weight loss is less clear. Therefore, we assessed myocardial triglyceride (TG) content, pericardial fat and cardiac function in obese patients with insulin-dependent type 2 diabetes before and 16 weeks after Roux-en-Y gastric bypass (RYGB) surgery. PATIENTS: Ten obese patients with insulin-dependent type 2 diabetes [40% male, age 53·7 ± 8·9 years (mean ± SD)] scheduled to undergo RYGB surgery were included. MEASUREMENTS: Ectopic fat accumulation and cardiovascular function were assessed with magnetic resonance (MR) imaging and myocardial TG content with MR spectroscopy before and 16 weeks after RYGB surgery. RESULTS: Body mass index decreased from 41·3 ± 4·3 at baseline to 34·1 ± 2·8 kg/m(2) (P < 0·001) after 16 weeks. Glycemic control improved as well [HbA1c: 7·8 ± 1·1 to 6·8 ± 1·3% (62 ± 12 to 51 ± 14 mm) (P < 0·05)]. We did not observe an effect of the RYGB surgery on myocardial TG content, cardiac function or pulse wave velocity. There was a greater relative decrease in visceral (-35·5 ± 9·6%) as compared to subcutaneous fat volume (-25·0 ± 6·3%) and in paracardial (-17·3 ±17·2%) as compared to epicardial fat volume (-6·4 ± 6·0%). CONCLUSIONS: This study shows that surgical-induced weight loss leads to a larger decrease in paracardial than epicardial fat. Myocardial TG and cardiovascular function did not change.

Higher insulin and glucagon-like peptide-1 (GLP-1) levels in healthy, young South Asians as compared to Caucasians during an oral glucose tolerance test.

OBJECTIVE: Higher insulin levels during an oral glucose test (OGTT) have been shown in South Asians. We aimed to investigate if this increased insulin response causes reactive hypoglycemia later on, and if an increased glucagon-like-peptide-1 (GLP-1) response, which could contribute to the hyperinsulinemia, is present in this ethnic group. METHODS: A prolonged, 6-h, 75-g OGTT was performed in healthy, young Caucasian (n=10) and South Asian (n=8) men. The glucose, insulin and GLP-1 response was measured and indices of insulin sensitivity and beta-cell activity were calculated. RESULTS: Age (Caucasians (CAU) 21.5±0.7 years vs South Asians (SA) 21.4±0.7 years (mean±SEM)) and body mass index (CAU 22.7±0.7 kg/m(2) vs SA 22.1±0.8 kg/m(2)) were comparable between the two groups. South Asian men were more insulin resistant, as indicated by a comparable glucose but significantly higher insulin response, and a significantly lower Matsuda index (CAU 8.7(8.6) vs SA 3.2(19.2), median(IQR)). South Asians showed a higher GLP-1 response, as reflected by a higher area under the curve for GLP-1 (CAU 851±99.8 mmol/l vs SA 1235±155.0 mmol/L). During the whole 6-h period, no reactive hypoglycemia was observed. CONCLUSION: Healthy, young South Asian men have higher insulin levels during an OGTT as compared to Caucasians. This does not, however, lead to reactive hypoglycemia. The hyperinsulinemia is accompanied by increased levels of GLP-1. Whether this is an adaptive response to facilitate hyperinsulinemia to overcome insulin resistance or reflects a GLP-1 resistant state has yet to be elucidated.

Pathogenesis of type 2 diabetes in South Asians.

The risk of developing type 2 diabetes mellitus (T2DM) is exceptionally high among both native and migrant South Asians. T2DM occurs more often and at a younger age and lower BMI, and the risk of coronary artery and cerebrovascular disease, and renal complications is higher for South Asians compared with people of White Caucasian descent. The high prevalence of T2DM and its related complications in South Asians, which comprise one-fifth of the total world's population, poses a major health and socioeconomic burden. The underlying cause of this excess risk, however, is still not completely understood. Therefore, gaining insight into the pathogenesis of T2DM in South Asians is of great importance. The predominant mechanism, in this ethnicity seems to be insulin resistance (IR) rather than an impaired ß-cell function. In this systematic review, we describe several possible mechanisms that may underlie or contribute to the increased IR observed in South Asians.

Short-term topiramate treatment does not improve insulin sensitivity or secretion in obese insulin-resistant women.

OBJECTIVE: Long-term treatment with topiramate reduces body weight and improves insulin sensitivity in obese humans. Our aim was to evaluate the effect of topiramate treatment for 4 weeks on insulin sensitivity and secretion, independent of weight loss. DESIGN: Randomized, double-blind, crossover, placebo-controlled study. METHODS: Thirteen obese (BMI 36.6 ± 1.3 kg/m(2) (mean ± s.e.m.)), insulin-resistant (homeostasis model of assessment-insulin resistance 2.0 ± 0.2) women received topiramate (T, maximum dose of 75 mg) and placebo (P) for 4 weeks, separated by a 4-week washout period. Insulin sensitivity and ß-cell function were assessed using a two-step hyperinsulinemic euglycemic clamp with stable isotopes and a hyperglycemic clamp. RESULTS: Hepatic and peripheral insulin sensitivities were not affected by topiramate treatment (glucose disposal rate (step 1 (insulin infusion rate 10 MU/M(2) per min) T: 17.5 ± 0.8 vs P: 18.5 ± 1.0 µmol/kg(LBM) per min, t=1.016, P=0.33; step 2 (insulin infusion rate 40 mU/m(2) per min) T: 27.9 ± 3.2 vs P: 28.8 ± 1.9 µmol/kg(LBM) per min, t=0.418, P=0.68)). Subjects lost a small amount of weight during the topiramate period (T: -1.0 ± 0.2 vs P: -0.1 ± 0.2 kg, t=2842, P=0.15). There were no changes in body fat mass, blood pressure, and fasting glucose. ß-Cell function was not affected by topiramate as evidenced by an unaltered area under the curve of early (0-10 min; T: 1929.6 ± 265.7 vs P: 2024.7 ± 333.6 pmol/l, t=-0.357, P=0.73) and late (80-120 min; T: 28,017.7 ± 5029.9 vs P: 31,567.7 ± 5376.2 pmol/l, t=-1.481, P=0.16) phase insulin levels during hyperglycemia. The use of topiramate was associated with significant side effects such as paresthesia, nausea, dizziness, and concentration problems. CONCLUSIONS: Low-dose topiramate treatment for 4 weeks, relative to placebo, had no significant effect on insulin sensitivity in overweight/obese adult females without established diabetes.

Quality of life in type 2 diabetes mellitus after a very low calorie diet and exercise.

OBJECTIVE: To evaluate whether the addition of exercise to a very low calorie diet (VLCD) has beneficial short- and long-term effects on health-related quality of life (QoL) in obese patients with type 2 diabetes mellitus (T2DM). METHODS: We included 27 obese, insulin-dependent T2DM patients in a 16-week VLCD study, of whom 13 participated simultaneously in an exercise program (VLCD+E). Before, immediately after and 18 months after the intervention anthropometric measurements, glucoregulation and QoL (SF-36, HADS, NHP and MFI-20) were assessed. Patients were compared to healthy lean and obese (matched for body mass index) controls matched for gender and age. RESULTS: At baseline, T2DM patients had significantly worse QoL scores in 18 and 14 of the 22 subscales of the QoL questionnaires, compared to lean and obese controls, resp. The 16-week VLCD (n=27) decreased bodyweight (-25.4±1.3 kg, p<0.0001, p=0.179 between groups), and improved glucoregulation (HbA1c -1.3±0.3%, p<0.0001, p=0.488 between groups) and 9 (VLCD-only) and 11 (VLCD+E) of the 22 subscales of QoL. After 18 months, in the VLCD+E group the QoL subscales did not differ from those in obese controls and only 4 of the 22 subscales were significantly worse compared to lean controls. However, in the VLCD-only group 17 and 13 of the 22 QoL subscales were significantly worse compared to the lean and obese controls, resp. CONCLUSION: A 16-week VLCD induces considerable weight loss, metabolic amelioration, and major improvements in QoL in obese T2DM patients. The addition of exercise is of paramount importance for the maintenance of better QoL.