L. Fezeu

BMI in relation to sperm count: an updated systematic review and collaborative meta-analysis

BACKGROUND The global obesity epidemic has paralleled a decrease in semen quality. Yet, the association between obesity and sperm parameters remains controversial. The purpose of this report was to update the evidence on the association between BMI and sperm count through a systematic review with meta-analysis. METHODS A systematic review of available literature (with no language restriction) was performed to investigate the impact of BMI on sperm count. Relevant studies published until June 2012 were identified from a Pubmed and EMBASE search. We also included unpublished data (n = 717 men) obtained from the Infertility Center of Bondy, France. Abstracts of relevant articles were examined and studies that could be included in this review were retrieved. Authors of relevant studies for the meta-analysis were contacted by email and asked to provide standardized data. RESULTS A total of 21 studies were included in the meta-analysis, resulting in a sample of 13 077 men from the general population and attending fertility clinics. Data were stratified according to the total sperm count as normozoospermia, oligozoospermia and azoospermia. Standardized weighted mean differences in sperm concentration did not differ significantly across BMI categories. There was a J-shaped relationship between BMI categories and risk of oligozoospermia or azoospermia. Compared with men of normal weight, the odds ratio (95% confidence interval) for oligozoospermia or azoospermia was 1.15 (0.93-1.43) for underweight, 1.11 (1.01-1.21) for overweight, 1.28 (1.06-1.55) for obese and 2.04 (1.59-2.62) for morbidly obese men. CONCLUSIONS Overweight and obesity were associated with an increased prevalence of azoospermia or oligozoospermia. The main limitation of this report is that studied populations varied, with men recruited from both the general population and infertile couples. Whether weight normalization could improve sperm parameters should be evaluated further.

Hypertension, diabetes mellitus and task shifting in their management in sub-Saharan Africa

Chronic diseases are becoming increasingly important in sub-Saharan Africa (SSA). The current density and distribution of health workforce suggest that SSA cannot respond to the growing demand for chronic disease care, together with the frequent infectious diseases. Innovative approaches are therefore needed to rapidly expand the health workforce. In this article, we discuss the evidences in support of nurse-led strategies for chronic disease management in SSA, with a focus on hypertension and diabetes mellitus.

Total and Specific Polyphenol Intakes in Midlife Are Associated with Cognitive Function Measured 13 Years Later

Polyphenols, and in particular flavonoids, are omnipresent plant-food components displaying biochemical properties possibly beneficial to brain health. We sought to evaluate the long-term association between total and class-specific polyphenol intake and cognitive performance. Polyphenol intake was estimated using the Phenol-Explorer database applied to at least six 24-h dietary records collected in 1994-1996 as part of the SU.VI.MAX (Supplémentation en Vitamines et Minéraux Antioxydants) study. The cognitive performance of 2574 middle-aged adults participating in the cohort was assessed in 2007-2009 using the following four neuropsychological tests: phonemic and semantic fluency, the RI-48 Cued Recall test, the Trail Making test, and Forward and Backward Digit Span. Inter-correlations among the test scores were estimated with principal component analysis. Associations between polyphenol intake and cognition were assessed by multivariate linear regression and ANCOVA. In multivariate models, high total polyphenol intake was associated with better language and verbal memory (P = 0.01) but not with executive functioning (P = 0.09). More specifically, intake of catechins (P = 0.001), theaflavins (P = 0.002), flavonols (P = 0.01), and hydroxybenzoic acids (P = 0.0004) was positively associated with language and verbal memory, especially with episodic memory assessed by the RI-48 test. In contrast, negative associations between scores on executive functioning and intake of dihydrochalcones (P = 0.01), catechins (P = 0.01), proanthocyanidins (P = 0.01), and flavonols (P = 0.01) were detected. High intake of specific polyphenols, including flavonoids and phenolic acids, may help to preserve verbal memory, which is a salient vulnerable domain in pathological brain aging. Further investigations are needed to clarify the observed negative associations regarding executive functioning.

Determinants of vitamin D status in Caucasian adults: influence of sun exposure, dietary intake, sociodemographic, lifestyle, anthropometric, and genetic factors.

Very few studies have investigated the determinants of serum vitamin D levels using a set of variables that include simultaneously sun exposure, phototype, dietary intake, sociodemographics, anthropometric, lifestyle data, and genetic polymorphisms. Our objective was to investigate the associations between all these parameters and vitamin D status in a large sample of French adults. This cross-sectional survey was based on 1,828 middle-aged Caucasian adults from the SU.VI.MAX (SUpplémentation en VItamines et Minéraux AntioXydants) study. Plasma 25-hydroxyvitamin D (25OHD) concentration was lower among women (P<0.0001), older subjects (P=0.04), obese/underweight (P<0.0001), those living at higher latitudes (P<0.0001), those whose blood draw occurred in early spring (P<0.0001), less physically active (P<0.0001), with low sun exposure (P<0.0001), and with no-to-low alcohol intake (P=0.0001). Mutant GC rs4588 and rs7041 single nucleotide polymorphisms were associated with lower and higher 25OHD concentrations, respectively (P<0.0001). Dietary intake was not a major determinant of vitamin D status (P=0.7). This study provides an overall picture of determinants of vitamin D status. Several modifiable factors were identified, such as daily-life moderate sun exposure, physical activity, and normal-weight maintenance, which should be targeted by public health policies in order to improve vitamin D status in the general population, while avoiding active/intensive sun exposure, in line with recommendations for skin cancer prevention.

New biomarkers of coffee consumption identified by the non-targeted metabolomic profiling of cohort study subjects.

Coffee contains various bioactives implicated with human health and disease risk. To accurately assess the effects of overall consumption upon health and disease, individual intake must be measured in large epidemiological studies. Metabolomics has emerged as a powerful approach to discover biomarkers of intake for a large range of foods. Here we report the profiling of the urinary metabolome of cohort study subjects to search for new biomarkers of coffee intake. Using repeated 24-hour dietary records and a food frequency questionnaire, 20 high coffee consumers (183–540 mL/d) and 19 low consumers were selected from the French SU.VI.MAX2 cohort. Morning spot urine samples from each subject were profiled by high-resolution mass spectrometry. Partial least-square discriminant analysis of multidimensional liquid chromatography-mass spectrometry data clearly distinguished high consumers from low via 132 significant (p-value<0.05) discriminating features. Ion clusters whose intensities were most elevated in the high consumers were annotated using online and in-house databases and their identities checked using commercial standards and MS-MS fragmentation. The best discriminants, and thus potential markers of coffee consumption, were the glucuronide of the diterpenoid atractyligenin, the diketopiperazine cyclo(isoleucyl-prolyl), and the alkaloid trigonelline. Some caffeine metabolites, such as 1-methylxanthine, were also among the discriminants, however caffeine may be consumed from other sources and its metabolism is subject to inter-individual variation. Receiver operating characteristics curve analysis showed that the biomarkers identified could be used effectively in combination for increased sensitivity and specificity. Once validated in other cohorts or intervention studies, these specific single or combined biomarkers will become a valuable alternative to assessment of coffee intake by dietary survey and finally lead to a better understanding of the health implications of coffee consumption.

Associations between dietary patterns and arterial stiffness, carotid artery intima-media thickness and atherosclerosis:

Background Few studies have examined the association between global diet, assessed through dietary patterns, and arterial structure and function. The aim of this study was to investigate the relationship between carotid-femoral pulsewave velocity (PWV), common carotid-arteries intima-media thickness (CCA-IMT) and plaques with dietary patterns measured 7.5 years earlier. Design A prospective cohort study between diet and markers of structure and function of large arteries. Methods Dietary patterns (linear combination of food consumption) were identified using principal component analysis among 1026 middle-aged participants in the SUpplémentation en VItamines et Minéraux AntioXydants (SU.VI.MAX) vascular substudy. Dietary data were based on repeated 24-h dietary records (at least three records during 2 years) obtained at inclusion. Carotid-femoral PWV was used to assess aortic stiffness. Carotid ultrasound examination included measurements of CCA-IMT and carotid plaques. Results Four dietary patterns were identified. In multivariate models, a significant positive association was observed between PWV and a dietary pattern positively correlated with meat and alcohol consumption and negatively correlated with fibers, vitamins B9 and C, β-carotene and calcium consumption. Adjusted PWV mean across tertiles of this pattern score was 11.15,11.26 and 11.58m/s in the first, second and third tertiles, respectively (P for trend = 0.03). Others dietary patterns were not associated with PWV and we detected no association between dietary patterns and IMT or plaques. Conclusion This study suggests that a nutritionally poor dietary pattern, characterized by a high meat and alcohol consumption and low micronutrients intake, is related to an increased stiffening of large arteries.

Interpretation of Plasma PTH Concentrations According to 25OHD Status, Gender, Age, Weight Status, and Calcium Intake: Importance of the Reference Values

CONTEXT Reference values for plasma PTH assessment were generally established on small samples of apparently healthy subjects, without considering their 25-hydroxyvitamin D (25OHD) status or other potential modifiers of PTH concentration. OBJECTIVE Our objective was to assess ranges of plasma PTH concentration in a large sample of adults, stratifying by 25OHD status, age, gender, weight status, and calcium intake. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional survey is based on 1824 middle-aged Caucasian adults from the Supplémentation en Vitamines et Minéraux Antioxydants study (1994). MAIN OUTCOME MEASURES Plasma PTH and 25OHD concentrations were measured by an electrochemoluminescent immunoassay. Extreme percentiles of plasma PTH concentrations were assessed specifically in subjects who had plasmatic values of 25OHD of 20 ng/mL or greater and 30 ng/mL or greater. RESULTS Among subjects with 25OHD status of 20 ng/mL or greater, the 97.5th percentile of plasma PTH concentration was 45.5 ng/L. By using this value as a reference, 5% of the subjects with plasma 25OHD less than 20 nmol/L had a high plasma PTH level, reflecting secondary hyperparathyroidism. Among vitamin D-replete subjects (25OHD status of 20 ng/mL or greater), the 97.5th percentile of plasma PTH was higher in overweight/obese subjects (51.9 vs 43.5 ng/L among normal weight subjects). CONCLUSIONS The reference value for plasma PTH defined in this vitamin D-replete population was far below the value currently provided by the manufacturer (65 ng/L) and varied according to overweight status. These results may contribute to improve the diagnosis of primary and secondary hyperparathyroidism and subsequent therapeutic indication.

Prospective association between the dietary inflammatory index and metabolic syndrome: Findings from the SU.VI.MAX study

BACKGROUND AND AIMS The prevention of the metabolic syndrome (MetS) is of major concern and nutrition has been shown to modulate at least partly MetS risk. Our objective was to investigate whether a pro-inflammatory diet was associated with a higher risk of MetS and its components in a large cohort of French adults. METHODS AND RESULTS A total of 3726 participants from the Supplémentation en Vitamines et Minéraux AntioXydants (SU.VI.MAX) cohort were included in this study. The MetS status was identified at baseline and after 13 years of follow-up using self-reported medication, data from clinical investigations and biological measurements. The dietary inflammatory index (DII) was computed using repeated 24 h-dietary records (n = 10.1 ± 3.1). Logistic and linear regression analyses were conducted to assess the prospective association of the DII (as Q, quartiles) with the incidence of MetS and with the traits contributing to the MetS-definition (blood pressure, glycaemia, triglycerides, HDL-cholesterol, waist circumference). A diet with pro-inflammatory properties, as expressed by higher DII scores, was significantly associated with a higher risk of developing the MetS (OR comparing Q4 to Q1: 1.39, 95% confidence interval 1.01-1.92, P = 0.047). Moreover, higher DII scores were associated with higher systolic and diastolic blood pressure (Ptrend across quartiles = 0.03 and 0.05, respectively) and triglycerides (Ptrend = 0.01), and with lower HDL-cholesterol (Ptrend = 0.03). CONCLUSION A higher DII score was prospectively associated with a higher risk of MetS, with associations with blood pressure, triglycerides and HDL-cholesterol. Promotion of a healthy diet exhibiting anti-inflammatory properties may contribute to prevent cardio-metabolic disorders.

Association between Adherence to Nutritional Guidelines, the Metabolic Syndrome and Adiposity Markers in a French Adult General Population

Introduction Few studies have focused on the association between diet quality scores and the Metabolic Syndrome (MetS), a multi-component condition predictive of cardiovascular diseases (CVD) and death. The present study aims at investigating, in a cross-sectional design, the association between adherence to the French dietary guidelines through an a priori score – the French Nutrition and Health Program-Guideline Score (PNNS-GS) – and cardiovascular risk factors (CVRF) including the MetS and adiposity markers. Methods 7902 French adults participating in the NutriNet-Santé study (an on-going web-based cohort study) attended a clinical and biological examination between January 2011 and November 2012: a fasting blood sample was drawn, blood pressure and body composition (bio-impedance) were measured. Multivariate linear and logistic regression models were used to assess the association between PNNS-GS and CVRF or the MetS. Results An increase of PNNS-GS was significantly negatively associated with waist circumference (WC), systolic and diastolic blood pressure (SBP and DBP) and serum triglycerides concentrations. From bottom to top quartile of PNNS-GS, SBP decreased from 129.9 to 128.8 mm Hg, DBP from 76.7 to 75.9 mm Hg, serum triglycerides concentrations from 110.8 to 104.6 mg/dL and WC from 94.8 to 90.1 cm for men and 81.3 to 78.9 cm for women. All adiposity markers (waist and hip circumference, % body fat, % trunk fat, % leg fat) were markedly reduced across quartiles of PNNS-GS and linearly. Individuals with a better PNNS-GS (quartile 4 vs quartile 1) were less likely to have the MetS (OR=0.71, 95% CI: 0.56-0.89). Conclusion The negative association between a higher adherence to the French dietary guidelines and a number of CVRF, the MetS prevalence and regional adiposity supports the importance of promoting the PNNS dietary guidelines in the population for the prevention of cardiometabolic abnormalities and hence, cardiovascular diseases.

Relationship Between Nutrition and Blood Pressure: A Cross-Sectional Analysis from the NutriNet-Santé Study, a French Web-based Cohort Study

BACKGROUND Hypertension is the most prevalent chronic disease worldwide. Lifestyle behaviors for its prevention and control are recommended within worldwide guidelines. Nevertheless, their combined relationship with blood pressure (BP) level, particularly in the general population, would need more investigations. Our aim in this study was to evaluate the relative impact of lifestyle and nutritional factors on BP level. METHODS Cross-sectional analyses were performed using data from 8,670 volunteers from the NutriNet-Santé Study, an ongoing French web-based cohort study. Dietary intakes were assessed using three 24-hour records. Information on lifestyle factors was collected using questionnaires and 3 BP measurements following a standardized protocol. Age-adjusted associations and then multivariate associations between systolic BP (SBP) and lifestyle behaviors were estimated using multiple linear regressions. RESULTS SBP was higher in participants with elevated body mass indices (BMIs). Salt intake was positively associated with SBP in men but not in women. The negative relationship between consumption of fruits and vegetables and SBP was significant in both sexes. Alcohol intake was positively associated with SBP in both sexes; physical activity was not. The 5 parameters representing the well-accepted modifiable factors for hypertension reduction plus age and education level, accounted for 19.7% of the SBP variance in women and 12.8% in men. Considering their squared partial correlation coefficient, age and BMI were the most important parameters relating to SBP level. Salt intake was not associated with SBP in either sex after multiple adjustments. CONCLUSIONS BMI was the main contributory modifiable factor of BP level after multiple adjustments.