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Background: Obesity is a risk factor for both vitamin D deficiency and cardiovascular disease. A link between vitamin D status optimisation and improved cardiometabolic profile among adults with obesity could inform public health initiatives. Methods: PubMed, Embase and Web of Science were searched for interventional studies examining the effects of vitamin D status improvement on cardiovascular risk factors (anthropometric measures, lipid profile, blood pressure, glucose tolerance) among nondiabetic adults with obesity. Results: Seventeen publications reporting results from 11 different studies were included. Number of participants ranged from 34 to 1179 subjects. Duration was between 6 weeks and 4 years. Vitamin D was administered as a supplement in ten studies (1000 IU daily to 120 000 IU fortnightly). In one study, participants were advised to increase sunlight exposure and dietary vitamin D intake. The random and fixed-effects meta-analysis showed that vitamin D significantly increased systolic blood pressure and LDL-C levels. The fixed-effects model also indicated a significant decrease in triglyceride levels, which was not evident using the random-effects model. Caution should be given to these results given the small number of studies used and the high heterogeneity between studies for the two latter outcomes. Additionally, a subset of eligible studies with compatible data presentation was included in the meta-analysis. Conclusion: This systematic review highlights a paucity of interventional studies examining the effects of vitamin D status improvement on cardiovascular risk factors among otherwise healthy adults with obesity. Large-scale studies at pharmacologically relevant doses and with sufficient duration are warranted.

Background Irisin, a novel myokine, has been shown to increase following vigorous exercise, with studies suggesting that it mediates some of the beneficial effects of exercise. Irisin might play a role in ‘browning’ of white adipocytes, thus increasing energy expenditure. The role of irisin in exercise and energy expenditure in subjects with diabetes mellitus type 2 (DMT2) remains largely unknown. We aimed to investigate the association between circulating irisin and habitual physical activity in subjects with and without DMT2. Material and methods In this cross-sectional study, 164 Saudi adults: 81 non-DMT2 controls [age: (mean ± SD) 51·6 ± 10·9; BMI: 29·6 ± 4·3 kg/m2] and 83 DMT2 subjects [age: 54·3 ± 10·3 year; BMI: 29·4 ± 4·7 kg/m2] were studied. Anthropometric and fasting serum biochemical data were collected. Circulating irisin was measured using an enzyme-linked immunosorbent assay (ELISA). Frequency intensity time (FIT) index was used to assess the level of habitual physical activity. Results We observed significantly higher levels of irisin in DMT2 subjects than in controls (P < 0·001). FIT index was positively associated (r = 0·20, P = 0·03) with circulating irisin in controls only. Additionally, irisin levels were significantly higher in tertile 3 (0·75 ± 0·07 μg/mL) than tertile 1 (0·49 ± 0·06 μg/mL) of the FIT index in healthy controls, whilst no such relation with physical activity was observed in DMT2 subjects. Conclusion This cross-sectional study has shown a weak association of irisin with physical activity levels in healthy controls but not in DMT2 subjects, suggesting the possibility of discordant regulation in the condition of DMT2.

Background Visceral Adiposity Index (VAI) is a gender-specific mathematical index estimated with the use of simple anthropometric (body mass index and waist circumference) and biochemical (triglycerides and high density lipoprotein cholesterol) parameters. Recent studies have shown that VAI reflects accurately the degree of visceral adiposity and insulin resistance. However, up to now, VAI has not been evaluated if it correlates with carbohydrate metabolism disorders, as well as with adipokine secretion from the fat mass. Methods In a cohort of 308 out of 414 adult Saudi subjects screened for the study, detailed personal medical history, anthropometrics and metabolic/hormonal profiles were obtained. Additionally, the circulating concentrations of several circulating adipokines, namely adiponectin, leptin, tumour necrosis factor-α (TNF-α) and resistin, were measured. Results Stepwise multivariate analysis showed that VAI was the sole determinant of adiponectin levels (R2 = 0·07, beta ± SE: −0·25 ± 0·05), while BMI and female gender predicted leptin levels (R2 = 0·26, 0·10 ± 0·01 and 0·61 ± 0·15, respectively). Furthermore, the presence of impaired fasting glucose (IFG)/diabetes was predicted only by age and VAI. Conclusions We report for the first time the direct relations of VAI with adipose tissue secretion, as well as with functional glycaemic disorders. Because VAI is estimated easily with data obtained in everyday practice, it could be used as an indirect index of adiponectin levels and the risk of impaired glucose metabolism.

Background The hallmark of vascular inflammation is the recruitment of circulating leucocytes, primarily monocytes, macrophages and T lymphocytes, into the vascular wall; however, the link between monocyte/macrophage activation and hypertension has not been established as yet. In this study, we determined how sCD163, a monocyte/macrophage soluble scavenger receptor and immunomodulator, relates to arterial blood pressure (BP) in hypertensive Saudi individuals. Materials and methods A total of 90 (30 non-hypertensive obese, 30 hypertensive obese and 30 lean normotensive controls) adult Saudi subjects, aged 40–60 years, participated in this cross-sectional study. Serum fasting blood glucose, triglycerides, total cholesterol, HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C), leptin, adiponectin, resistin, insulin, tumour necrosis factor-alpha (TNF-α), PAI-1, angiotensin II, high-sensitivity C-reactive protein (hsCRP) and sCD163 were measured in all subjects studied. Results sCD163 concentrations were significantly increased in obese hypertensive patients compared to controls (P = 0·016). Positive correlations between sCD163 and body mass index (BMI) (r = 0·27, P = 0·01), systolic BP (r = 0·25, P = 0·01), diastolic BP (r = 0·33, P = 0·001), LDL-C (r = 0·21, P = 0·04), TNF-α (r = 0·23, P = 0·02) and hsCRP (r = 0·33, P = 0·008) were observed. Positive correlations between sCD163 and diastolic BP (r = 0·23, P = 0·04) and LDL-C (r = 0·22, P = 0·03) remained significant after controlling for BMI. Conclusions Taken together, these data demonstrate that the monocyte/macrophage activation-related sCD163 is positively associated with BMI and increased arterial BP with the elevation in diastolic BP being independent of the BMI.

Eur J Clin Invest 2011; 41 (9): 987–994 Abstract Background Prostate disease incidence is expected to rise among developing nations secondary to increased prevalence of obesity and the elderly. Although many case–control studies have associated obesity to prostate cancer aggressiveness, few have correlated markers of prostate pathology to biomarkers of visceral obesity and insulin resistance, using an apparently healthy cohort. This study aims to fill this gap. Materials and methods The 219 consenting adult Arab men, aged 30–70 years, were included in this cross-sectional study. Demographics were noted and anthropometrics measured. Fasting blood samples were extracted, and glycaemic and lipid profile were determined using routine laboratory methods. Serum adipocytokines and inflammatory markers were measured using multiplex assays. Total prostate-specific antigen (tPSA), free PSA (fPSA), parathyroid-related protein (PTHrP) and endoglin were measured using enzyme-linked immunosorbent assays. Results Serum triglycerides and waist–hip ratio (WHR) were significantly and positively associated with circulating (tPSA) levels in all subjects (P

Eur J Clin Invest 2010; 40 (12): 1063–1066 Abstract Background Epidemiological studies have suggested an increased prevalence of metabolic syndrome (MS) among adults in the Middle-East. This study aims to determine the prevalence of MS in a large cohort of Saudi children and adolescents. Materials and methods In this cross-sectional observational study, a total of 1231 randomly selected Saudi children and adolescents aged 10–18 years were recruited. Subjects’ information was generated from a database of more than 10 000 Saudi citizens from the existing Biomarkers Screening in Riyadh Program (RIYADH Cohort), Saudi Arabia. Anthropometrics included body mass index, blood pressure, as well as waist and hip circumferences. Fasting blood glucose and lipid profile were determined using routine laboratory procedures. The modified definition of ATP-III (NHANES III) was used for the diagnosis of MS. Results Overall prevalence of complete MS was 9·4% [confidence interval (CI) 7·8–11·0]. Age-adjusted prevalence according to the European standard population is 5·8%. Boys had a comparable MS prevalence with girls [10·3% (CI 8·2–12·4) vs. 8·1% (CI 5·7–10·5), respectively (P = 0·20)]. Low HDL-cholesterol was the most prevalent of all MS risk factors, affecting 86% (CI 85·0–88·6) and hypertriglyceridemia, the second most prevalent, affecting 33% (CI 30·6–35·8) of the subjects. Conclusions The prevalence of MS manifestations among Arab children is extremely high, with dyslipidemia being the most common MS abnormality. Screening for dyslipidemia among Saudi children is warranted especially among those most at risk. Scientific inquiry into the molecular causes of these manifestations should be pursued as a first step in the discovery of aetiological therapies.

Background Irisin, a novel myokine, increases energy expenditure and glucose tolerance and, thus, improves carbohydrate homeostasis in humans. This hormone has potential therapeutic applications for weight loss and improvement in insulin resistance in subjects with obesity and diabetes mellitus type 2 (T2DM). In this cross-sectional study, we aimed to associate circulating levels of irisin and several anthropometric and metabolic parameters among Arab children. Methods A cohort of 153 Saudi children, 81 boys [age: 12·4 ± 3·2 years; BMI: 19·5 ± 5·9 kg/m2] and 72 girls: [age: 12·9 ± 3·2 years; BMI: 20·6 ± 5·2], were examined. Anthropometry was obtained, and fasted bloods were collected for biochemical analyses. Irisin was assessed by a specific enzyme-linked immunosorbent assay (ELISA). Results Girls had higher circulating irisin levels than boys (P = 0·04). There were several significant correlations between circulating irisin and fasting blood glucose (FBG) (r = −0·35, P < 0·001), sagittal abdominal diameter (SAD) (r = −0·34, P < 0·001) and HDL cholesterol (r = 0·17, P = 0·04) across the entire cohort studied. Notably in girls, but not in boys, HOMA-IR correlated negatively with irisin levels (r = −0·32, P = 0·02), as previously noted in adults. FBG was a significant predictor of circulating irisin (R2 = 0·16) followed by SAD. In multivariate linear regression analysis, after controlling for potential confounders such as gender, age and BMI, irisin levels were independently associated with FBG (β = −0·34, P = 0·01), particularly in girls. Conclusion Serum irisin levels were higher in girls than in boys and correlated negatively with HOMA-IR. They were also independently associated with FBG predominantly in girls, suggesting that this hormone may play a crucial role in glucose metabolism from an early age.

Our findings showed that p53 mRNA expression levels are upregulated in epicardial adipose tissue (EAT) from patients with heart failure (HF). This upregulation was also found in myocardium [2]. Our group have described its upregulation in EAT by sympathetic system. This article is protected by copyright. All rights reserved.

The hallmark of vascular inflammation is the recruitment of circulating leucocytes, primarily monocytes, macrophages and T lymphocytes, into the vascular wall; however, the link between monocyte/macrophage activation and hypertension has not been established as yet. In this study, we determined how sCD163, a monocyte/macrophage soluble scavenger receptor and immunomodulator, relates to arterial blood pressure (BP) in hypertensive Saudi individuals.A total of 90 (30 non-hypertensive obese, 30 hypertensive obese and 30 lean normotensive controls) adult Saudi subjects, aged 40-60 years, participated in this cross-sectional study. Serum fasting blood glucose, triglycerides, total cholesterol, HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C), leptin, adiponectin, resistin, insulin, tumour necrosis factor-alpha (TNF-α), PAI-1, angiotensin II, high-sensitivity C-reactive protein (hsCRP) and sCD163 were measured in all subjects studied.sCD163 concentrations were significantly increased in obese hypertensive patients compared to controls (P=0.016). Positive correlations between sCD163 and body mass index (BMI) (r=0.27, P=0.01), systolic BP (r=0.25, P=0.01), diastolic BP (r=0.33, P=0.001), LDL-C (r=0.21, P=0.04), TNF-α (r=0.23, P=0.02) and hsCRP (r=0.33, P=0.008) were observed. Positive correlations between sCD163 and diastolic BP (r=0.23, P=0.04) and LDL-C (r=0.22, P=0.03) remained significant after controlling for BMI.Taken together, these data demonstrate that the monocyte/macrophage activation-related sCD163 is positively associated with BMI and increased arterial BP with the elevation in diastolic BP being independent of the BMI.

Prostate disease incidence is expected to rise among developing nations secondary to increased prevalence of obesity and the elderly. Although many case-control studies have associated obesity to prostate cancer aggressiveness, few have correlated markers of prostate pathology to biomarkers of visceral obesity and insulin resistance, using an apparently healthy cohort. This study aims to fill this gap.The 219 consenting adult Arab men, aged 30-70 years, were included in this cross-sectional study. Demographics were noted and anthropometrics measured. Fasting blood samples were extracted, and glycaemic and lipid profile were determined using routine laboratory methods. Serum adipocytokines and inflammatory markers were measured using multiplex assays. Total prostate-specific antigen (tPSA), free PSA (fPSA), parathyroid-related protein (PTHrP) and endoglin were measured using enzyme-linked immunosorbent assays.Serum triglycerides and waist-hip ratio (WHR) were significantly and positively associated with circulating (tPSA) levels in all subjects (P0·01). Systolic blood pressure (SBP), adiponectin, active plasminogen activator inhibitor-1 (aPAI-1) and insulin-like growth factor-1 (IGF-1) had significant inverse associations to tPSA. Stepwise linear regression revealed that adiponectin, IGF-1, WHR and PTHrP explained 30% of variance in tPSA levels (P0·0001), while SBP, resistin and BMI explained 18·7% of variance in endoglin (P = 0·001).The associations of adiponectin and WHR strengthen the link between insulin resistance and visceral adiposity to prostate volume markers among apparently healthy Arab men. Follow-up studies are needed to extend these preliminary findings so that early interventions can be provided to those at increased risk.

Epidemiological studies have suggested an increased prevalence of metabolic syndrome (MS) among adults in the Middle-East. This study aims to determine the prevalence of MS in a large cohort of Saudi children and adolescents.In this cross-sectional observational study, a total of 1231 randomly selected Saudi children and adolescents aged 10-18 years were recruited. Subjects' information was generated from a database of more than 10,000 Saudi citizens from the existing Biomarkers Screening in Riyadh Program (RIYADH Cohort), Saudi Arabia. Anthropometrics included body mass index, blood pressure, as well as waist and hip circumferences. Fasting blood glucose and lipid profile were determined using routine laboratory procedures. The modified definition of ATP-III (NHANES III) was used for the diagnosis of MS.Overall prevalence of complete MS was 9·4% [confidence interval (CI) 7·8-11·0]. Age-adjusted prevalence according to the European standard population is 5·8%. Boys had a comparable MS prevalence with girls [10·3% (CI 8·2-12·4) vs. 8·1% (CI 5·7-10·5), respectively (P = 0·20)]. Low HDL-cholesterol was the most prevalent of all MS risk factors, affecting 86% (CI 85·0-88·6) and hypertriglyceridemia, the second most prevalent, affecting 33% (CI 30·6-35·8) of the subjects.The prevalence of MS manifestations among Arab children is extremely high, with dyslipidemia being the most common MS abnormality. Screening for dyslipidemia among Saudi children is warranted especially among those most at risk. Scientific inquiry into the molecular causes of these manifestations should be pursued as a first step in the discovery of aetiological therapies.