Prevalence and predictors of vitamin D inadequacy amongst Lebanese osteoporotic women.

In Middle-Eastern countries, more particularly in Lebanon, the incidence of vitamin D deficiency has been found to be surprisingly high in schoolchildren and young individuals. However, the prevalence and risk factors for vitamin D inadequacy amongst Lebanese osteoporotic women seeking medical health care has never been studied. We analysed vitamin D-inadequacy risk factors among the 251 Lebanese postmenopausal osteoporotic women (from both Muslim and Christian communities) who participated in a vitamin D international epidemiological study. Vitamin D inadequacy prevalence (25-hydroxyvitamin D (25(OH)D) , 30 ng/ml) was 84.9%. 25(OH)D was negatively correlated with BMI (r 20.41; P<0.001) and positively correlated with educational level (r 0.37; P<0.001) and self-reported general health (r 0.17; P<0.01). No significant correlation was found with age and no seasonal variation was observed. There was no significant correlation between 25(OH)D and sun exposure index or vitamin D-rich food consumption. However, 25(OH)D strongly correlated with vitamin D supplement intake (r 0.48; P<0.0001). Muslim community participants had lower 25(OH)D levels compared with their Christian counterparts (P<0.001). They also had higher BMI, lower educational level and vitamin D supplement consumption and followed more frequently a dress code covering the arms (P<0.0001 for all variables). In a multivariate model, in Muslims, inadequate vitamin D supplements and a dress code covering the arms are the independent predictors of 25(OH)D inadequacy (P<0.001 for both variables). However, in Christians, the predictors are inadequate vitamin D supplements, high BMI and low educational level (P<0.001; P=002 and P=0.02 respectively). There is an urgent need to increase vitamin D supplement use in Middle-Eastern osteoporotic women, more particularly in those from the Muslim community.

Evaluation of a multilocus variable-number tandem-repeat analysis scheme for typing human Brucella isolates in a region of brucellosis endemicity.

Brucellosis remains an important anthropozoonosis worldwide. Brucella species are genetically homogeneous, and thus, the typing of Brucella species for epidemiological purposes by conventional molecular typing methods has remained elusive. Although many methods could segregate isolates into the phylogenetically recognized taxa, limited within-species genetic diversity has been identified. Recently, multilocus variable-number tandem-repeat analysis (MLVA) was found to have a high degree of resolution when it was applied to collections of Brucella isolates from geographically widespread locations, and an assay comprising 16 such loci (MLVA-16) was proposed. This scheme includes eight minisatellite loci (panel 1) and eight microsatellites (panel 2, which is subdivided into panels 2A and 2B). The utility of MLVA-16 for the subtyping of human Brucella isolates from geographically restricted regions needs to be further evaluated, and genotyping databases with worldwide coverage must be progressively established. In the present study, MLVA-16 was applied to the typing of 42 human Brucella isolates obtained from 41 patients recovered from 2002 to 2006 at a tertiary-care center in Lebanon. All isolates were identified as Brucella melitensis by MLVA-16 and were found to be closely related to B. melitensis isolates from neighboring countries in the Middle East when their genotypes were queried against those in the web-based Brucella2007 MLVA database (http://mlva.u-psud.fr/). Panel 2B, which comprised the most variable loci, displayed a very high discriminatory power, while panels 1 and 2A showed limited diversity. The most frequent genotype comprised seven isolates obtained over 7 weeks in 2002, demonstrating an outbreak from a common source. Two isolates obtained from one patient 5 months apart comprised another genotype, indicating relapsing disease. These findings confirm that MLVA-16 has a good discriminatory power for species determination, typing of B. melitensis isolates, and inferring their geographical origin. Abbreviated panel 2B could be used as a short-term epidemiological tool in a small region of endemicity.

Development and evaluation of real-time polymerase chain reaction assays on whole blood and paraffin-embedded tissues for rapid diagnosis of human brucellosis.

This study aimed at developing a real-time polymerase chain reaction (PCR) assay for the rapid diagnosis of human brucellosis on clinical specimens. Three assays with hybridization probe detection on the LightCycler instrument were developed and compared targeting the 16S-23S internal transcribed spacer region (ITS) and the genes encoding for omp25 and omp31. All assays showed 100% analytical sensitivity and 100% specificity when tested on 28 consecutive clinical isolates of Brucella sp. and 19 clinical isolates of common Gram-negative and Gram-positive bacterial pathogens, respectively. The ITS assay was the most sensitive with a limit of detection of 2 genome equivalents per PCR reaction. This assay was then clinically validated prospectively with 354 samples (351 whole blood samples and 3 paraffin-embedded tissues) collected from 340 patients, 24 samples from patients with active brucellosis including 2 relapsing cases, 31 with treated brucellosis, and 299 seronegative patients where brucellosis was initially suspected. The clinical sensitivity, specificity, and positive and negative predictive values of the ITS assay were 66.7%, 99.7%, 94.1%, and 97.6%, compared with culture at 77%, 100%, 100%, and 97.3%, respectively. The difference in sensitivity between culture and ITS-PCR was not statistically significant (P = 0.71). Both relapsing cases were PCR positive. Treated patients were PCR negative. All 3 assays were positive on tissue samples, but the omp25 and omp31 assays did not detect Brucella sp. DNA in blood samples. Because omp31 is not present in Brucella abortus, these data indicate that the 28 tested isolates are most likely Brucella melitensis. ITS-PCR is rapid and could augment the clinical laboratory diagnosis of human brucellosis.

Serum adiponectin and leptin levels in relation to the metabolic syndrome, androgenic profile and somatotropic axis in healthy non-diabetic elderly men.

OBJECTIVE: The relationships between adipocytokines, sex steroids and the GH/IGF-I axis is poorly studied and subject to controversy in healthy elderly male subjects. We investigated the association between both adiponectin and leptin, and the metabolic syndrome (MetS), lipid parameters, insulin sensitivity, sex steroids and IGF-I in healthy non-diabetic Lebanese men. DESIGN AND METHODS: In this cross-sectional study, a total of 153 healthy non-diabetic men aged 50 and above (mean age 59.3 +/- 7 years) had a detailed clinical and biological evaluation. Subjects were classified according to the National Cholesterol Education Program criteria of the MetS. Insulin sensitivity was determined by the Quantitative Insulin Sensitivity Check Index (QUICKI). RESULTS: Subjects with the MetS had lower adiponectin and higher leptin levels (P < 0.0001 for both variables) compared with individuals without the MetS. Adiponectin was significantly correlated with waist size, triglycerides, high-density lipoprotein (HDL) cholesterol and QUICKI (r = -0.33, -0.26, 0.45 and 0.36 respectively, P < 0.0001 for all variables). The relation between adiponectin and HDL cholesterol, triglycerides and QUICKI remained significant after adjustment for age and body mass index (BMI). Also, leptin was strongly correlated with waist size and QUICKI (r = 0.63 and -0.63 respectively, P < 0.001 for both variables). However, its relation to the lipid profile was weak (for cholesterol r = 0.16, P < 0.05; for triglycerides r = 0.17, P < 0.05) and disappeared after adjustment for BMI. Adiponectin was positively correlated with sex hormone-binding globulin (SHBG) (r = 0.39, P < 0.001) and inversely correlated with free-androgen index (r = -0.24, P < 0.01), estradiol and dehydroepiandrosterone sulfate (r = -0.165, P < 0.05; r = -0.21, P < 0.01 respectively). This difference remained significant for SHBG after adjustment for age and BMI (r = 0.20, P < 0.005). Finally, leptin was inversely correlated with total testosterone and SHBG (r = -0.44, P < 0.001; r = -0.30, P < 0.001 respectively); the relation with testosterone remained significant after adjustment for BMI. No significant relationship of either adiponectin or leptin with GH or IGF-I values was observed. In a stepwise multiple regression analysis, the independent predictors of adiponectin were HDL cholesterol, QUICKI, age and BMI (P < 0.0001, P = 0.005, P = 0.002 and P = 0.047 respectively) while for leptin, it was QUICKI, waist size and testosterone (P < 0.0001, P < 0.0001 and P = 0.004 respectively). The adjusted R2 values were 0.34 and 0.55. CONCLUSION: Our results show that in a healthy elderly male population, both adiponectin and leptin are related to insulin sensitivity, independent of age and BMI. While adiponectin is independently related to triglycerides and HDL cholesterol, the weak relationship of leptin to the lipid profile is completely mediated by BMI. In addition, and more interestingly, both adipocytokines are strongly associated with sex steroids. We speculate that SHBG is regulated by adiponectin and that there is an inhibitory effect of testosterone on the adiponectin gene. Further studies are needed to fully elucidate these relationships.

Pravastatin does not affect insulin sensitivity and adipocytokines levels in healthy nondiabetic patients.

BACKGROUND: The effect of statins on insulin resistance is controversial and poorly studied in nondiabetic subjects. In addition, the effect of statins on leptin and adiponectin has never been studied. METHODS: Forty healthy nondiabetic volunteers (22 men and 18 women) aged 28 to 72 were randomized either to placebo or pravastatin 40 mg daily for a 12-week period. Insulin resistance, assessed using the Quantitative Insulin Sensitivity Check Index (QUICKI), as well as serum leptin and adiponectin levels, was measured at baseline and at the end of therapy. RESULTS: Pravastatin treatment decreased total cholesterol, low-density lipoprotein cholesterol, and triglycerides levels by 24%, 32%, and 14%, respectively ( P < .05 for all), but did not affect glucose and insulin levels, the (QUICKI) index, and adiponectin and leptin levels. When stratification was performed according to QUICKI index or sex, no significant differences were observed in the prevalues and postvalues of leptin, adiponectin, or QUICKI index in the pravastatin group. Adiponectin, leptin, and QUICKI index were statistically higher in women than in men ( P < .001 for both variables). Adiponectin was negatively correlated with body mass index (BMI; r = -0.39, P < .05) and positively correlated with the QUICKI index ( r = 0.54, P < .001) and with high-density lipoprotein cholesterol ( r = 0.50, P < .01). The relation between adiponectin and QUICKI index remained significant after adjustment for sex and BMI ( P = .005 and P = .007, respectively). Leptin was only related to BMI ( r = 0.57, P < .001) and to sex ( P < .001) with no significant correlations with lipid parameters or QUICKI index. Both sex and BMI are independent predictors of leptin ( P < .001 and P < .001). CONCLUSION: A 12-week treatment with pravastatin 40 mg/d does not change the QUICKI index and leptin and adiponectin levels in healthy volunteers. In addition, our results emphasize the importance of sex and BMI in the determination of both adiponectin and leptin. Adiponectin was also related to QUICKI index, whereas this relation was not found with leptin.

Impact of different metabolic syndrome classifications on the metabolic syndrome prevalence in a young Middle Eastern population.

The metabolic syndrome (MetS) prevalence in a young Middle Eastern population has never been studied. We studied this prevalence in a randomly selected population of Lebanese students using different MetS classifications. Three hundred eighty-one subjects aged 18 to 30 years were included in the study. Anthropometric and biological parameters (waist circumference [WC], systolic and diastolic blood pressures, fasting plasma glucose, triglycerides, total cholesterol, high-density lipoprotein cholesterol, and homeostasis model assessment [HOMA] index to assess insulin resistance) were measured. Receiver operating characteristic (ROC) curves were generated to determine population-specific cutoff values for MetS parameters and HOMA index. The MetS prevalence was calculated using the National Cholesterol Education Program's Adult Treatment Panel III (ATP-III), the actualized ATP-III, and our cutoffs, either with or without HOMA index as an extra risk factor. The MetS prevalence using the ATP-III and the actualized ATP-III was, respectively, 5.25% and 5.28%. It increased to 9.19% when using our cutoff values and to 12.64% when HOMA index was added. This increase was significant only in men. The identified cutoff values are, for WC, 91 cm in women and 99.5 cm in men and, for HOMA index, 2.32. Among the MetS components, WC was the best MetS predictor, whereas fasting plasma glucose was the poorest. Our study shows that the MetS prevalence in Lebanon is comparable with other countries. In addition, we identified in our population new cutoff points for MetS parameters and HOMA index that allow the detection of a higher number of subjects with the MetS, mainly in the male population.

Vitamin D in relation to metabolic risk factors, insulin sensitivity and adiponectin in a young Middle-Eastern population.

OBJECTIVES: Several studies suggest a link between circulating 25-hydroxyvitamin D (25(OH)D) and metabolic risk factors. However, this relation has been mainly studied in elderly and/or obese subjects. In addition, the relation between 25(OH)D and adiponectin is unclear. The purpose of this study is to look at these relations in non-obese young individuals. DESIGN: We investigated the relation between serum 25(OH)D and adiposity, blood pressure, glucose metabolism, lipid profile, and adiponectin in 381 randomly selected university students (201 males and 180 females, mean age 23.9+/-3.9). RESULTS: In the overall population, 25(OH)D is significantly inversely correlated with body mass index (BMI), systolic blood pressure (SBP), waist circumference (WC), fasting plasma glucose (FPG), insulin levels, and homeostasis model assessment of insulin resistance (HOMA index) and positively correlated with adiponectin and high density lipoprotein-cholesterol (P<0.01 for all variables). In males, these correlations are still significant for BMI, SBP, WC, and adiponectin (P=0.02, P=0.01, P=0.04 and P=0.01 respectively); also, 25(OH)D is inversely correlated with low density lipoprotein (LDL)-cholesterol (P=0.007). In females, 25(OH)D is only inversely correlated with FPG and HOMA index (P<0.001 and P=0.03 respectively). In multivariate regression analysis models, after adjustment for sex and BMI, 25(OH)D is an independent predictor of FPG and SBP (P=0.032 and P=0.05 respectively) in the overall population, while in males 25(OH)D is a predictor of LDL-cholesterol and SBP independently of BMI (P=0.007 and P=0.035 respectively). CONCLUSION: In non-obese young subjects, we observe new relationships between 25(OH)D and several metabolic risk factors and adiponectin. Further research is needed to elucidate the gender differences and to look at the relation between 25(OH)D and adiponectin.

Osteoprotegerin in relation to body weight, lipid parameters insulin sensitivity, adipocytokines, and C-reactive protein in obese and non-obese young individuals: results from both cross-sectional and interventional study.

OBJECTIVE: We analyzed the relation of osteoprotegerin (OPG) with insulin sensitivity, lipid profile, serum glutamic pyruvic transaminase (SGPT), adipocytokines, and C-reactive protein (CRP) in obese and non-obese subjects. METHODS: In the study, 170 subjects (106 obese and 64 non-obese, sex ratio female/male=2.03) were included. Thirty-two obese subjects were reevaluated 6 months after the weight loss induced by bariatric surgery. RESULTS: OPG did not differ between obese and non-obese subjects (respective mean values 5.17 and 4.96 pmol/l) or according to gender, but was positively correlated with age (P<0.0001 for both groups). OPG was statistically higher in 18 obese diabetic subjects compared with non-diabetics (P=0.03). After adjustment for age, no significant correlation was found between OPG and body mass index (BMI), waist, systolic and diastolic blood pressure, cholesterol, triglycerides, high density lipoprotein (HDL) cholesterol, leptin, and adiponectin in both the obese and non-obese subjects. However, OPG was positively correlated with homeostasis model assessment (HOMA) index and SGPT levels in obese subjects at baseline (r=0.295, r=0.20, P<0.05) and after adjustment for age (r=0.28, r=0.20, P<0.05). OPG was also significantly correlated with CRP; this correlation persisted after adjustment for age in obese subjects (r=0.30, P<0.01). In a multivariate analysis in the obese group, HOMA index and CRP were independent predictors of OPG while SGPT was not. Six months post-surgery, OPG did not change, despite a significant reduction in glucose, SGPT, cholesterol, triglycerides, CRP, and leptin values (P=0.02, P=0.006, P=0.007, P<0.001, P<0.001, P<0.001 respectively) and a significant increase in adiponectin and HDL values (P<0.001 for both variables). CONCLUSION: Our results show that in obese subjects, OPG is not related to BMI. However, we describe new relationships between OPG and both HOMA index and CRP.

Cytokine expression profile of sensitized human T lymphocytes following in vitro stimulation with amoxicillin.

Since the withdrawal of penicillin determinants from the market, in addition to the hazard of re-exposing the patient to the drug, skin testing for the diagnosis of penicillin allergy has become less accurate and less standardized. The assay currently used, the lymphocyte transformation test (LTT), lacks sufficient sensitivity, and requires the use of radioactive material. The objective of this study was to establish an accessible and reliable method for the safe diagnosis of penicillin allergy. Peripheral blood mononuclear cells (PBMC) were isolated from 18 patients who were allergic to penicillin and 12 control subjects using the Ficoll-Hypaque method. The isolated, sensitized cells were stimulated in vitro with amoxicillin (1 mg/mL). Stimulation with phytohemagglutinin A (PHA) was used as the positive control. Transcriptional expression of specific cytokines (IL-2, -4, -5 and -13, TGF-beta, TNF-alpha and IFN-gamma) was assessed by RT-PCR. IFN-gamma expression was also evaluated by ELISPOT. Secreted levels of IL-2, -5 and IFN-gamma were measured by ELISA. All of these assays were performed two or five days, post-stimulation. This study of the in vitro diagnosis of penicillin allergy by the measurement of cytokine concentration in the supernatants of sensitized lymphocytes cultures involved the largest number of patients to-date. The Delta values (difference in cytokine concentration in the supernatants before and after stimulation) were compared between cases and controls using different statistical tests (Student's t test and the Mann-Whitney rank test). Of the various tests performed in this study, measurement of secreted cytokines using ELISA was the most sensitive and specific (80% and 100% respectively). In vitro stimulation of human lymphocytes sensitized to amoxicillin is a safe and useful test for the diagnosis of penicillin allergy if the ELISA is used to measure cytokine expression. The advantages are that it can be performed by many laboratories since kits to determine cytokines are widely available, and it can be done without the need for particularly specialized equipment.

Variations in prostate-specific antigen free/total ratio in acute stress.

Serum prostate-specific antigen complexed to alpha2-macroglobulin is occult and is not detected by conventional immunoassays. Conditions affecting alpha2-macroglobulin levels may alter the specificity of prostate-specific antigen free/total ratio in predicting prostate cancer. A group of patients (n=24) undergoing surgical stress due to a coronary artery bypass grafting was followed pre- and postoperatively up to 6 days. Total and free prostate-specific antigen, alpha2-macroglobulin, and C-reactive protein were measured by electrochemiluminescence, immunonephelometry, and immunoturbidimetry, respectively. Total prostate-specific antigen and C-reactive protein increased significantly postsurgery and remained elevated. Free/total ratio correlated negatively with C-reactive protein only (p = 0.000) using xtgee panel data analysis, after correction for plasma volume changes using albumin. Increased C-reactive protein may reflect falsely decreased free/total ratio. Therefore, prostate-specific antigen free/total ratio would be more reliable if interpreted in combination with information about CRP. However, it is recommended to defer the measurement of free/total ratio if CRP is highly elevated.

Circulating osteoprotegerin is correlated with lipid profile, insulin sensitivity, adiponectin and sex steroids in an ageing male population.

OBJECTIVE: The relationship between osteoprotegerin (OPG) and lipid profile, insulin sensitivity, adipocytokines and sex steroids has been poorly studied and subject to controversy. The purpose of this study was to look at the correlates of OPG in an elderly male population. DESIGN: One hundred and fifty-one nondiabetic, elderly Lebanese men (age range 50-83) were recruited in this cross-sectional study based on voluntary enrolment. MEASUREMENTS: In all the subjects, serum OPG levels were measured and related to clinical parameters (age, waist, body mass index (BMI), systolic and diastolic blood pressure), as well as to metabolic and hormonal parameters. The following fasting laboratory measurements were performed: plasma glucose and insulin levels, total cholesterol, triglycerides and HDL cholesterol, adiponectin, leptin, as well as sex steroids (testosterone, SHBG, free androgen index, ooestradiol, DHEAS), GH and IGF-1. QUICKI index was calculated as a measure of insulin sensitivity. RESULTS: OPG levels were significantly correlated with age (r = 0.28, P < 0.0001) but not with BMI, waist, systolic or diastolic blood pressure. There was a trend towards higher OPG levels in subjects without, compared to subjects with the metabolic syndrome (3.58 +/- 1.28 vs. 3.26 +/- 1.04 pmol/l, P = 0.09). OPG was negatively correlated with fasting glucose and triglyceride levels (r = -0.18, P = 0.031 and r = -0.19, P = 0.02, respectively) and positively correlated with the QUICKI index (r = 0.17, P = 0.033), HDL cholesterol (r = 0.21, P = 0.009) and adiponectin levels (r = 0.27, P = 0.001). No significant correlations were reported with total or LDL cholesterol levels and with leptin levels. After adjustment for age, OPG is still correlated with triglycerides (r = -0.19, P = 0.02), glucose (r = -0.21, P = 0.011) and adiponectin (r = 0.19, P = 0.02). Finally, OPG was positively associated with SHBG (r = 0.31, P < 0.001) and negatively associated with free androgen index (r =-0.346, P < 0.001); both correlations persisted after adjustment for age (r = 0.21, P = 0.009 and r = -0.23, P = 0.005, respectively). No significant correlation was found between OPG and oestradiol levels while a weak negative correlation was demonstrated with DHEAS (r = -0.18, P = 0.025). Also, no significant correlation was found between OPG and GH or IGF-1 values. In a multiple regression analysis with a stepwise model, the main determinants of OPG were free androgen index and adiponectin (P < 0.0001 and P = 0.015, respectively). CONCLUSION: Our results show that circulating OPG levels are favourably associated with some components of the metabolic syndrome. Also, for the first time, an association between OPG and adiponectin is described. Finally, the negative correlation we found between OPG and free androgen index may suggest a potential role of OPG in the increase in cardiovascular disease related to ageing and sex steroid deficiency.