Parathyroid hormone and insulin resistance in distinct phenotypes of severe obesity: a cross-sectional analysis in middle-aged men and premenopausal women

Nutritional Status after Roux-En-Y (Rygb) and One Anastomosis Gastric Bypass (Oagb) at 6-Month Follow-Up: A Comparative Study

Introduction: Roux-en-Y gastric bypass (RYGB) and one anastomosis gastric bypass (OAGB) are two effective bariatric surgical procedures with positive outcomes in terms of weight loss, comorbidities remission, and adverse events profiles. OAGB seems to carry a higher risk of malnutrition, but existing data are controversial. The aim of this study is to objectively evaluate and compare malnutrition in patients undergoing RYGB and OAGB. Methods: Retrospective monocentric study of obese patients undergoing RYGB or OAGB between the 15 September 2020 and the 31 May 2021. Nutritional status was assessed using the Controlling Nutritional Status (CONUT) score and compared between groups. The primary outcome was the mean CONUT score at 6 months. The secondary outcomes included the incidence of malnutrition, comorbidities, including hypertension, insulin resistance and type II diabetes mellitus, and weight loss. Results: 78 patients were included: 30 underwent RYGB and 48 underwent OAGB. At 6-Month Follow-Up there was no difference between groups in the mean CONUT score nor in incidence of malnutrition. In both groups, the nutritional status significantly worsened 6 months after surgery (preoperative and postoperative score of 0.48 ± 0.9 and 1.38 ± 1.5; p = 0.0066 for RYGB and of 0.86 ± 1.5 and 1.45 ± 1.3; p = 0.0422 for OAGB). Type II Diabetes mellitus (DMII) and hypertension remission were significant in the OAGB group with a 100% relative remission in the DMII-OAGB group (p = 0.0265), and a 67% relative remission in the hypertension-OAGB group (p = 0.0031). Conclusions: No difference in nutritional status has been detected between patients undergoing RYGB or OAGB at the 6-Month Follow-Up. Both procedures may have significant mal-absorptive effects leading to decline in nutritional status. OAGB may be more efficacious in inducing DMII and hypertension remission. Larger prospective studies dedicated specifically to nutritional status after gastric bypass are needed to confirm the impact of different bypass procedures on nutritional status.

Impact of 30° Reserve Trendelenburg Position on Lung Function in Morbidly Obese Patients Undergoing Laparoscopic Sleeve Gastrectomy

Background

This study aimed to evaluate the impact of patients' positioning before and after intubation with mechanical ventilation, and after extubation on the lung function and blood oxygenation of patients with morbid obesity, who had a laparoscopic sleeve gastrectomy.

Methods

Patients with morbid obesity (BMI ≥ 30 kg/m², ASA I – II grade) who underwent laparoscopic sleeve gastrectomy at our hospital from June 2018 to January 2019 were enrolled in this prospective study. Before intubation, after intubation with mechanical ventilation, and after extubation, arterial blood was collected for blood oxygenation and gas analysis after posturing the patients at supine position or 30° reverse Trendelenburg position (30°-RTP).

Results

A total of 15 patients with morbid obesity were enrolled in this self-compared study. Pulmonary shunt (Qs/Qt) after extubation was significantly lower at 30°-RTP (18.82 ± 3.60%) compared to that at supine position (17.13 ± 3.10%, p < 0.01). Patients' static lung compliance (Cstat), during mechanical ventilation, was significantly improved at 30°-RTP (36.8 ± 6.7) compared to that of those in a supine position (33.8 ± 7.3, p < 0.05). The PaO₂ and oxygen index (OI) before and after intubation with mechanical ventilation were significantly higher at 30°-RTP compared to that at supine position, and in contrast, the P_A−aO₂ before and after intubation with mechanical ventilation was significantly reduced at 30°-RTP compared to that at supine position.

Conclusion

During and after laparoscopic sleeve gastrectomy, patients with morbid obesity had improved lung function, reduced pulmonary shunt, reduced P_A−aO₂ difference, and increased PaO₂ and oxygen index at 30°-RTP compared to that supine position.

Laparoscopic Banded One Anastomosis Gastric Bypass: A Single-Center Series

INTRODUCTION

Laparoscopic one anastomosis gastric bypass (LOAGB) is a relatively new procedure for the treatment of morbid obesity and related comorbidities. On average, this procedure results in good postoperative weight loss with a low complication rate. Recent publications suggest that dumping syndrome and weight regain might be reduced by placing a silicone ring over the gastric pouch during the procedure, so called laparoscopic banded one anastomosis gastric bypass (LBOAGB).

METHODS

86 patients undergoing LBOAGB between 2018 and 2020 were enrolled in this retrospective study. Hospital records were used to assess weight loss, comorbidity resolution, and any complications either in the short or medium term.

RESULTS

54 Female and 32 male patients were included with a mean age of 43 years (25-64), preoperative body mass index of 42 kg/m² (35-49), and preoperative weight of 114 kg (86-162). Thirty-four patients presented with type 2 diabetes (39.5%), 42 patients (49%) diagnosed with hypertension, 24 presented with OSAS (28%), and 21 (24%) hypercholesterolaemia patients were included. In total, 36 patients were diagnosed with multiple comorbidities. The operative data showed an average operative time of 48 minutes with 3.4% of patients suffering from early (minor) complications and 2.3% with a late (minor) complication. One patient required reoperation due to intra-abdominal bleeding. The median length of hospital stay was 2.5 days. Median follow-up was 18 months (5-36). In that period, no patient required ring removal or conversion to Roux-en-Y gastric bypass surgery. Food intolerance/vomiting was present in 1 patient (1.1%), bile reflux was present in 1 patient (1.1%), and no stomal ulcers were observed. Mean % excess weight loss at 12 and 24 months was 72% and 80%, respectively. Fifty-two out of 86 patients (60%) had a complete resolution of comorbidities. A CONUT score >2 (mild malnutrition) was found in 40% of patients, while a CONUT score 0-1 was found in 60% of patients.

CONCLUSION

LBOAGB shows promising results in terms of safety and efficacy in the short term. Further prospective studies will be required to evaluate the consistency of the results in the long term.

The Effects of Bariatric Surgery and Gastrectomy on the Absorption of Drugs, Vitamins, and Mineral Elements

Bariatric surgery, which is an effective treatment for obesity, and gastrectomy, which is the primary treatment method for gastric cancer, alter the anatomy and physiology of the digestive system. Weight loss and changes in the gastrointestinal tract may affect the pharmacokinetic parameters of oral medications. Both bariatric and cancer patients use drugs chronically or temporarily. It is important to know how surgery affects their pharmacokinetics to ensure an effective and safe therapy. The Cochrane, PubMed, and Scopus databases were searched independently by two authors. The search strategy included controlled vocabulary and keywords. Studies show that bariatric surgery and gastrectomy most often reduce the time to maximum plasma concentration (t_max) and decrease the maximum plasma concentration (C_max) in comparison with the values of these parameters measured in healthy volunteers. Vitamin and mineral deficiencies are also observed. The effect depends on the type of surgery and the properties of the drug. It is recommended to use the drugs that have been tested on these groups of patients as it is possible to monitor them.

Metabolic surgery for type II diabetes: an update

Bariatric operations have been documented in clinical trials to promote remission or dramatic improvement of Type II Diabetes Mellitus and related comorbidities. Herein we review randomized trials and meta-analyses published during the last 20 years on the results of bariatric/metabolic surgery in obese patients with type 2 diabetes with the aim of highlighting the scientific evidence available. Several studies and RCTs in the last 20 years have showed outstanding results of bariatric/metabolic surgery on Type II diabetes and comorbidities in patients with either BMI > 35 kg/m² or BMI < 35 kg/m². They have established that bariatric procedures are superior to non-surgical interventions for inducing weight loss and amelioration of type 2 diabetes, even in patients with a BMI between 30 and 35 kg/m². The physiopatologic changes that improve glucose homeostasis after bariatric surgery remain unclear but glycemic control is improved after sleeve gastrectomy, duodenal-jejunal bypass, Roux-en-Y gastric bypass, gastric banding, One Anastomosis Gastric Bypass, and biliopancreatic diversion. Nevertheless, it is suggested that the various gastrointestinal procedures may have different effects and mechanisms of action. Metabolic surgery will help integrate knowledge and multidisciplinary expertise to provide a combination of conservative and surgical treatments for Type II diabetes. These treatments must be considered as complementary options and not alternative strategies, with the same goal of controlling diabetes and achieving cure.

Neurocognitive and Psychopathological Predictors of Weight Loss After Bariatric Surgery: A 4-Year Follow-Up Study

Twenty to thirty percent of patients experience weight regain at mid and long-term follow-up. Impaired cognitive functions are prevalent in people suffering from obesity and in those with binge eating disorder, thereby, affecting the weight-loss outcomes. The aim of our study was to investigate neurocognitive and psychopathological predictors of surgical efficacy in terms of percentage of excess weight loss (%EWL) at follow-up intervals of one year and 4-year. Psychosocial evaluation was completed in a sample of 78 bariatric surgery candidates and included psychometric instruments and a cognitive battery of neuropsychological tests. A schedule of 1-year and 4-year follow-ups was implemented. Wisconsin Sorting Card Test total correct responses, scores on the Raven's Progressive Matrices Test, and age predicted %EWL at, both, early and long-term periods after surgery while the severity of pre-operative binge eating (BED) symptoms were associated with lower %EWL only four years after the operation. Due to the role of pre-operative BED in weight loss maintenance, the affected patients are at risk of suboptimal response requiring ongoing clinical monitoring, and psychological and pharmacological interventions when needed. As a result of our findings and in keeping with the latest guidelines we encourage neuropsychological assessment of bariatric surgery candidates. This data substantiated the rationale of providing rehabilitative interventions tailored to cognitive domains and time specific to the goal of supporting patients in their post-surgical course.

Does the Metabolically Healthy Obese Phenotype Protect Adults with Class III Obesity from Biochemical Alterations Related to Bone Metabolism?

Obesity negatively affects the relationship between markers and micronutrients of bone metabolism. Testing the hypothesis that the metabolically healthy obese phenotype might be protected by those alterations was the aim of this study. A cross-sectional study was carried out in adults with class III obesity classified in Metabolically Healthy Obese (MHO) and Metabolically Unhealthy Obese (MUHO), according to the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (NCEP ATP III) criteria. Anthropometric, biochemical, and clinical variables were analyzed for sample characterization. To evaluate bone metabolism, markers (alkaline phosphatase and parathyroid hormone—PTH) and related nutrients (vitamin D, vitamin B12, calcium, phosphorus, magnesium, potassium and zinc) were analyzed. A total of 223 adults with class III obesity aged 41.20 ± 10.15 years were included. The MHO phenotype was identified in 32.73% of the sample. After logistic regression, it was observed that inadequacies of calcium (OR: 4.11; 95% CI: 2.33–6.66), phosphorus (OR: 3.03; 95% CI: 1.98–5.79), vitamin D (OR: 5.01; 95% CI: 2.92–6.71) and PTH (OR: 5.45; 95% CI: 4.49–6.74) were significantly higher in the MUHO group compared to the MHO Group. This study showed that the MHO phenotype does not protect adults from alterations in markers and micronutrients of bone metabolism. However, the MUHO phenotype presents a higher risk for alterations related to bone metabolism, which can favor the emergence of metabolic bone diseases.

Parathyroid Gland Response to Vitamin D Deficiency in Type 2 Diabetes Mellitus: An Observational Study

Background

Studies have linked vitamin D deficiency with the risk of type 2 diabetes mellitus (T2DM) and to the development of chronic complication of diabetes. Vitamin D receptors (VDR) have been found in many tissues in the body including the pancreas, a finding that indicates its role in insulin secretion. In addition, many studies have demonstrated the role of vitamin D and its receptor in insulin sensitivity and signal transduction. Vitamin D deficiency is common throughout the world, but not all vitamin D deficiencies are accompanied by a rise in parathyroid hormone (PTH). The present study was conducted to assess vitamin D deficiency in type 2 diabetic patients in comparison to healthy control and to determine parathyroid gland response to vitamin D deficiency in both groups.

Methods

This observational study was performed during a period from January to October 2018. The study included 151 type 2 diabetic patients selected from three diabetes clinics and 43 age and sex-matched healthy subjects. Informed consent and clinical information were obtained from all participants before the study. Results of the laboratory analysis for serum 25-hydroxyvitamin D (25-OHD), PTH, calcium, and phosphorous were recorded. The data was analyzed using the statistical package for the social sciences (SPSS) Statistics 17.

Results

The results showed low vitamin D concentration in both groups; however, there was no significant difference in vitamin D concentration between diabetic patients and the control patients. A high percentage of PTH level was found in severe vitamin D deficient diabetic patients and healthy controls. The higher percentage of diabetic and normal subjects with mild vitamin D deficiency had a normal PTH level. All healthy subjects with vitamin D insufficiency showed normal PTH concentration. About 10% of diabetic patients with severe vitamin D deficiency had a low PTH level.

Conclusion

The population in our study was generally deficient in 25-OHD irrespective of diabetes mellitus, indicating a greater need for vitamin D supplementation. Not all vitamin D deficient patients have high PTH levels, a finding that supports the emergence of new criteria for vitamin D deficiency, diagnosis and treatment, and highlights the importance of testing PTH in this regard.

Parathyroid hormone in surgery-induced weight loss: no glucometabolic effects but potential adaptive response to skeletal loading

PURPOSE

Increased parathyroid hormone (PTH) is commonly associated with obesity, and its role in the pathogenesis of obesity-related glucometabolic abnormalities is uncertain. We aimed to explore the relationships of PTH with glucose/insulin homeostasis parameters before and after bariatric surgery-induced weight loss, and whether they depend or not on 25-hydroxyvitamin D (25OHD) status.

METHODS

We included 42 subjects (27 women, aged 40 ± 5 years, BMI 48.5 ± 7.3 kg/m²) without diabetes, chronic kidney disease, or hyperparathyroidism undergoing sleeve gastrectomy. The following parameters were evaluated before and 6 months after surgery: circulating levels of PTH, calcium, phosphorus, 25OHD, leptin, insulin growth factor (IGF)-1; 75-g oral glucose tolerance test to derive measures of insulin sensitivity (ISI) and secretion (Stumvoll index); dual-energy X-ray absorptiometry to assess fat distribution and bone mineral density.

RESULTS

Weight loss was accompanied by significant reduction of PTH levels (77.9 ± 19.1 vs. 60.5 ± 13.4 pg/ml; p = 0.005), without concomitant modification of 25OHD status. Both baseline PTH and its postoperative percent change resulted associated, with baseline fat mass (β = 0.615, p = 0.003) and its concurrent postoperative reduction (r = 0.419; p = 0.006), but neither with glucose homeostasis parameters nor their respective variations after weight loss. Interestingly, leptin reduction after weight loss was independently related to PTH change (β = 0.396, p = 0.015) and IGF-1 levels (β = 0.176, p = 0.059).

CONCLUSIONS

Circulating PTH decreases with fat mass reduction independent of 25OHD status, but it  is not associated with improvement of insulin resistance and related metabolic parameters. Leptin and PTH may mediate the cross-talk between adipose tissue and parathyroid glands, which possibly contributes to bone adaptation to excess body weight.

Obesity phenotypes: depot-differences in adipose tissue and their clinical implications

Obesity, defined as excess fat mass, increases risks for multiple chronic diseases, such as type 2 diabetes, cardiovascular disease, and several types of cancer. Beyond adiposity per se, the pattern of fat distribution, android or truncal as compared to gynoid or peripheral, has a profound influence on systemic metabolism and hence risk for obesity complications. Not only factors as genetics, environment, gender, and age account for the apparent compartmentalization of white adipose tissue (WAT) in the body. Indeed, the heterogeneity among different anatomical depots also appears to stem from their intrinsic diversity, including cellular developmental origin, proliferative capacity, glucose and lipid metabolism, insulin sensitivity, cytokine pattern, thermogenic ability, and vascularization. Under the obese condition, these depot-specific differences translate into specific WAT distribution patterns, giving rise to different cardiometabolic consequences. This review summarizes the clinical and mechanistic evidence for the depot-specific differences and the phenotypic characteristics of different WAT depots that link their depot-specific biology to obesity-specific complications.

Vitamin D status is not related to insulin resistance in different phenotypes of moderate obesity

Low plasma 25-hydroxy-vitamin D (25OHD) and high levels of parathyroid hormone (PTH) are associated with obesity and could play a role in the occurrence of complications such as insulin resistance. The objective of the study was to evaluate whether the relationship between 25OHD status and phosphocalcic parameters differs between metabolically healthy obese (MHO) and insulin-resistant obese (IRO). This cross-sectional study included 158 consecutive adults (121 females) with obesity (body mass index (BMI) 35.15 ± 2.8 kg/m²), aged 43.21 ± 13.6 years. Serum 25OHD, calcemia, phosphatemia, PTH, plasma lipids, fasting plasma glucose, insulin levels, and body composition were measured. Participants were classified as MHO (n = 65) or IRO (n = 93) based on homeostatic model assessment insulin-resistance value. IRO patients had a higher BMI (p = 0.001), waist circumference (p = 0.03), and trunk fat mass (p = 0.007) than MHO patients. Mean HbA1c (p = 0.03), triglycerides (p = 0.02), and hsCRP (p = 0.04) plasmatic levels were increased in the IRO group. No between-group difference was found on 25OHD, PTH, calcium, or phosphorus plasmatic levels. Only age-predicted 25OHD levels were identified among IRO participants, whereas no factors were identified in MHO. No predictive factors of PTH plasmatic level were identified in the IRO and MHO groups. Although MHO and IRO patients have different metabolic profiles, we did not detect any difference regarding either 25OHD or PTH. Insulin resistance was not a predictive factor of vitamin D status. Our results confirm the absence of link between vitamin D status and insulin resistance in moderate obesity.

Serum PTH reference values established by an automated third-generation assay in vitamin D-replete subjects with normal renal function: consequences of diagnosing primary hyperparathyroidism and the classification of dialysis patients

OBJECTIVE

To determine parathyroid hormone (PTH) reference values in French healthy adults, taking into account serum 25-hydroxyvitamin D (25OHD), renal function, age, gender, and BMI.

PARTICIPANTS AND MAIN BIOLOGICAL MEASUREMENTS

We studied 898 healthy subjects (432 women) aged 18-89 years with a normal BMI and estimated glomerular filtration rate (eGFR), 81 patients with surgically proven primary hyperparathyroidism (PHPT), and 264 dialysis patients. 25OHD and third-generation PTH assays were implemented on the LIAISON XL platform.

RESULTS

Median PTH and 25OHD values in the 898 healthy subjects were 18.8  ng/l and 23.6  ng/ml respectively. PTH was lower in subjects with 25OHD ≥30  ng/ml than in those with lower values. Among the 183 subjects with 25OHD ≥30  ng/ml, those aged ≥60 years (n=31) had higher PTH values than younger subjects, independent of 25OHD, BMI, and eGFR (P<0.001). Given the small number of subjects aged ≥60 years, we adopted the 95% CI of PTH values for the entire group of 183 vitamin D-replete subjects (9.4-28.9  ng/l) as our reference values. With 28.9  ng/l as the upper limit of normal (ULN) rather than the manufacturer's ULN of 38.4  ng/l, the percentage of PHPT patients with 'high' PTH values rose to 90.1% from 66.6% (P<0.001), and 18.6% of the dialysis patients were classified differently in view of the KDIGO target range (two to nine times the ULN).

CONCLUSION

When only subjects with 25OHD ≥30  ng/ml were included in the reference population, the PTH ULN fell by 22.4%, diagnostic sensitivity for PHPT improved, and the classification of dialysis patients was modified.

Relationship Between Parathormone and Obesity-Linked Disorders

BACKGROUND

In this study, we aimed to investigate whether high parathormone (PTH) levels in obese patients contribute to the metabolic complications of obesity.

METHODS

A total of 400 obese subjects aged 18-65 years were included. Anthropometric bioelectrical bioimpedance measures, blood tests, and 75 gram oral glucose tolerance test results were evaluated.

RESULTS

Of the 400 obese subjects, 335 were female. The mean age was 39 ± 10 years. The median body mass index was 36 (interquartile range 34-41). Subjects were divided into quartiles according to blood PTH levels. Groups included quartile 1 [n = 100, median PTH; 42 (range 36-45)], quartile 2 [n = 100, median PTH; 55 (51-59)], quartile 3 [n = 100, median PTH; 73 (68-78)], and quartile 4 [n = 100, median PTH; 99 (89-125)]. Quartiles were evaluated with a generalized linear model adjusted for age, sex, and season of recruitment. Systolic and diastolic blood pressure, fasting glucose, homeostatic model assessment-estimated insulin resistance, insulin sensitivity index, triglyceride level, and high-density lipoprotein cholesterol (HDL-C) were not different among quartiles. PTH and 25 hydroxyvitamin D (25(OH)D) were not associated with higher odds of prevalent metabolic syndrome in obese subjects (odds ratio, OR, 0.99 [95% confidence interval, CI, 0.981.00], P = 0.38 and 0.99 95% CI 0.96-1.01], P = 0.46, respectively). Decreased 25(OH)D levels were significantly correlated with higher odds of low HDL-C (OR 0.96 [95% CI 0.93-0.99], P = 0.04).

CONCLUSIONS

PTH does not contribute to the occurrence of metabolic components of obesity, but there is a positive correlation between 25(OH)D and HDL-C.

Vitamin D, parathyroid hormone and risk factors for coronary artery disease in an elderly Chinese population

AIMS

Low vitamin D status has been shown to be associated with coronary artery disease; most studies have involved in adults, but few have involved elderly people. We planned to research the association between vitamin D, parathyroid hormone (PTH) and coronary artery disease in elderly people.

METHODS

A population-based study was conducted among 1245 Chinese participants, aged 60-102 years, in the spring of 2013. Serum 25-hydroxyvitamin D (25 (OH)D) was measured by chemiluminescence assay. The levels of PTH were measured by the electrochemiluminescence immunoassay (ECLIA) method.

RESULTS

One thousand two hundred and forty-five participants, including 543 women (43.6%), were evaluated in 2013. The median concentrations of serum 25 (OH)D and PTH for the entire group were 16.8 ng/ml and 41.0 pg/ml, respectively. The prevalence rates of diabetes, hypertension, hyperlipidemia and coronary artery disease were significantly different across the 25 (OH)D quartiles. The prevalence rates of diabetes, hypertension, hyperlipidemia and coronary artery disease were also significantly different across the PTH quartiles. In logistic regression analyses, serum 25 (OH)D levels were associated with risk of coronary artery disease in single and multiple regression models (P < 0.05). Serum PTH levels were also associated with the risk of coronary artery disease in single and multiple regression models (P < 0.05). Subgroup analyses stratified by sex or age yielded similar results.

CONCLUSIONS

Serum vitamin D and PTH levels are independently associated with risk of coronary artery disease in a Chinese elderly population.

Vitamin D and parathyroid hormone status in pregnancy: effect on insulin sensitivity, β-cell function, and gestational diabetes mellitus

CONTEXT

Previous studies have yielded conflicting findings on the relationship between vitamin D deficiency/insufficiency and gestational diabetes mellitus (GDM). We hypothesized that PTH may be an underlying factor relevant to this potential association.

OBJECTIVE

This study sought to evaluate the effect of vitamin D and PTH status on insulin sensitivity, β-cell function, and glycemia in pregnancy.

SETTING AND DESIGN

Five-hundred-twenty-four women underwent a glucose challenge test (GCT) and oral glucose tolerance test (OGTT) in late second/early third trimester. The GCT/OGTT identified 142 women with GDM, 94 with gestational impaired glucose tolerance, 163 with an abnormal GCT and normal OGTT, and 125 with normal GCT and OGTT.

MAIN OUTCOMES

Glycemia was assessed by glucose tolerance status and area under the glucose curve (AUC(gluc)) on the OGTT. Insulin sensitivity and β-cell function were assessed by Matsuda index and Insulin Secretion-Sensitivity Index-2 (ISSI-2), respectively.

RESULTS

There were 166 women (31.7%) with vitamin D deficiency (25-OH-D < 50 nmol/L), 178 (34%) with insufficiency (25-OH-D ≥ 50 nmol/L and < 75 nmol/L), and 180 (34.3%) with sufficiency (25-OH-D ≥ 75 nmol/L). Vitamin D status was not associated with Matsuda index, ISSI-2, AUC(gluc), or glucose tolerance status. In contrast, ISSI-2 decreased and AUC(gluc) increased across ascending tertiles of PTH (P = .06 and P = .002, respectively). Indeed, the prevalence of GDM progressively increased from the first (22.6%) to second (25.8%) to third (33.5%) tertile of PTH (P < .001). On logistic regression analyses, the third tertile of PTH was independently associated with GDM (adjusted OR = 1.82; 95% CI, 1.09-3.02; P = .022), whereas vitamin D deficiency and insufficiency were not significant predictors of GDM.

CONCLUSIONS

Increased PTH, rather than vitamin D deficiency/insufficiency, is independently associated with dysglycemia in pregnancy.

Serum 25-hydroxyvitamin D levels and metabolic health status in extremely obese individuals

OBJECTIVE

Vitamin D deficiency is prevalent in obese individuals. 25-hydroxyvitamin D [25(OH)D] levels in metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO) adult individuals were examined and the relationship between 25(OH)D levels and other clinical parameters was evaluated.

METHODS

This is a retrospective chart review of outpatient medical records from the Nutrition and Weight Management Center at Boston Medical Center. Subjects were divided into two groups, MHO and MUO, using the homeostasis model assessment of insulin resistance criteria.

RESULTS

A total of 191 obese subjects were included in this analysis. The average body mass index (BMI) was 43.0 ± 9.2 kg/m(2) . Sixty-three subjects (33%) met criteria for MHO. MHO subjects had lower BMI and waist circumferences compared to MUO subjects. 25(OH)D levels were not significantly different between the two groups (P = 0.242). Overall, there were high prevalences of vitamin D deficiency (48.7%) and vitamin D insufficiency (33.0%). 25(OH)D levels were inversely correlated with BMI, body weight, waist circumferences, and HbA1c levels but not with blood pressure, total cholesterol, HDL, triglycerides, or LDL.

CONCLUSIONS

In extremely obese individuals, 25(OH)D levels were not related to metabolic health status or insulin resistance but correlated with the degree of adiposity.

Prospective associations of vitamin D status with β-cell function, insulin sensitivity, and glycemia: the impact of parathyroid hormone status

Previous studies have yielded conflicting findings on the relationship between low vitamin D (25-OH-D) and impaired glucose homeostasis. In this context, we hypothesized that combined assessment of 25-OH-D with its regulator parathyroid hormone (PTH) may be required for optimal evaluation of the impact of vitamin D status on glucose metabolism. Thus, we evaluated the prospective associations of 25-OH-D and PTH at 3 months postpartum with β-cell function (Insulin Secretion-Sensitivity Index-2 [ISSI-2]), insulin sensitivity (Matsuda index), and glycemia at 12 months postpartum in 494 women undergoing serial metabolic characterization. Notably, 32% of those with prediabetes/diabetes mellitus at 12 months postpartum had both vitamin D deficiency and PTH in the highest tertile at 3 months postpartum. On multiple-adjusted linear regression analyses, vitamin D deficiency/insufficiency with PTH in the highest tertile at 3 months independently predicted poorer β-cell function (P = 0.03) and insulin sensitivity (P = 0.01) and increased fasting (P = 0.03) and 2-h glucose (P = 0.002) at 12 months postpartum. In contrast, vitamin D deficiency/insufficiency with lower PTH did not predict these outcomes. In conclusion, only vitamin D deficiency/insufficiency with increased PTH is an independent predictor of β-cell dysfunction, insulin resistance, and glycemia, highlighting the need for consideration of the PTH/25-OH-D axis when studying the impact of vitamin D status on glucose homeostasis.

Muscle-bone and fat-bone interactions in regulating bone mass: do PTH and PTHrP play any role?

Metabolic bone disease occurs when there is a net loss in bone density. Osteoporosis, the most common metabolic bone disease, is a devastating problem and an increasingly major public health issue. A substantial body of evidence in the elderly population indicates that a relationship exists between the components of body weight and various measures of bone/mass, density, and function. Both muscle and fat contribute to the body's total weight and the intimate associations of muscle, fat, and bone are known. But the close functional interactions between muscle and bone or fat and bone are largely unidentified and have drawn much attention in recent years. Each of these tissues not only responds to afferent signals from traditional hormone systems and the central nervous systems but also secretes factors with important endocrine functions. Studies suggest that during growth, development, and aging, the relationship of muscle and fat with the skeleton possibly governs bone homeostasis and turnover. A better understanding of the endocrine function and the cellular and molecular mechanisms and pathways linking muscle or adipose tissues with bone anabolism and catabolism is a new avenue for novel pathways for anabolic drug discovery. These in turn will likely lead to more rational therapy toward increasingly prevalent disorders like osteoporosis. In this review, some of the recent works on the interaction of bone with muscle and fat are highlighted, and in so doing the role of parathyroid hormone (PTH), and PTH-related peptide (PTHrP) is surveyed.

Morning meal more efficient for fat loss in a 3-month lifestyle intervention

OBJECTIVE

To evaluate the effects of 2 low-calorie diets but with different distributions of calories throughout the day on weight loss and other major obesity-related metabolic parameters.

METHODS

We randomly assigned 42 nonsmoking homemakers (age = 46.3 ± 2.3 years, body mass index [BMI] = 35.7 ± 0.8 kg/m(2), mean ± SD) in 2 groups of 21 subjects (G1 and G2). The participants underwent a 3 month individualized Mediterranean-style diet (55% carbohydrate, 30% fat, 15% protein and fiber > 30 g), calorie (600 kcal daily deficit compared to the total energy expenditure measured by a metabolic Holter). Diets consisted of the same food and complied with cardiovascular disease prevention guidelines but differed in the distribution of calories throughout the day (G1: 70% breakfast, morning snack, lunch and 30% afternoon snack and dinner; G2: 55 breakfast, morning snack, lunch and 45% afternoon snack and dinner). Dual-energy X-ray absorptiometry was used for pre- and postintervention body composition assessment.

RESULTS

Thirty-six subjects completed the study (G1 = 18, G2 = 18). Both groups had significant improvements in body composition and metabolic parameters but G1 had enhanced results for weight loss (G1: -8.2 ± 3.0 kg; G2: -6.5 ± 3.4 kg; p = 0.028), waist circumference reduction (G1: -7 ± 0.6 cm; G2: -5 ± 0.3 cm; p = 0.033), and fat mass loss (G1: -6.8 ± 2.1 kg, G2: -4.5 ± 2.9 kg, p = 0.031; mean ± SD). Improvements were detected in both groups for blood pressure and blood and lipid parameters. G1 subjects showed a greater improvement in insulin sensitivity measured by homeostasis model assessment-estimated insulin resistance (G1: -1.37 ± 0.27, G2: -0.74 ± 0.12, p = 0.017).

CONCLUSIONS

These data suggest that a low-calorie Mediterranean diet with a higher amount of calories in the first part of the day could establish a greater reduction in fat mass and improved insulin sensitivity than a typical daily diet.

Role of vitamin D in the development of insulin resistance and type 2 diabetes

Vitamin D deficiency is mainly a consequence of insufficient sunlight induced vitamin D production in the skin and has been associated with various chronic diseases including type 2 diabetes. Experimental data have shown that vitamin D is important for glucose induced insulin secretion, improves insulin resistance, and exerts anti-inflammatory actions. Epidemiological studies have largely documented that a poor vitamin D status is associated with higher risk of insulin resistance and type 2 diabetes. The majority of randomized controlled trials (RCTs) in healthy or prediabetic individuals have, however, failed to demonstrate relevant vitamin D effects on insulin resistance or diabetes incidence. In patients with type 2 diabetes, a few RCTs reported some moderate effects of vitamin D on glycemic control and insulin resistance. While these findings warrant further in-depth studies, the current evidence is insufficient to recommend vitamin D supplementation for the prevention or treatment of type 2 diabetes.

Bone Remodeling and Energy Metabolism: New Perspectives

Bone mineral, adipose tissue and energy metabolism are interconnected by a complex and multilevel series of networks. Calcium and phosphorus are utilized for insulin secretion and synthesis of high energy compounds. Adipose tissue store lipids and cholecalciferol, which, in turn, can influence calcium balance and energy expenditure. Hormones long-thought to solely modulate energy and mineral homeostasis may influence adipocytic function. Osteoblasts are a target of insulin action in bone. Moreover, endocrine mediators, such as osteocalcin, are synthesized in the skeleton but regulate carbohydrate disposal and insulin secretion. Finally, osteoblasts and adipocytes originate from the same mesenchymal progenitor. The mutual crosstalk between osteoblasts and adipocytes within the bone marrow microenvironment plays a crucial role in bone remodeling. In the present review we provide an overview of the reciprocal control between bone and energy metabolism and its clinical implications.