Non-alcoholic fatty liver disease through the female lifespan: the role of sex hormones.

The prevalence of non-alcoholic fatty liver disease (NAFLD) differs between various stages of the female lifespan. The aim of this review is to summarize current evidence on the association of NAFLD and circulating sex hormones and to explore the pathogenesis of NAFLD within the context of (1) sex hormone changes during the reproductive, post-reproductive female life and beyond and (2) the in vitro and in vivo evidence on pharmacological modulation in women on menopausal hormone treatment (MHT) or endocrine therapy after breast cancer. The fluctuation in estrogen concentrations, the relative androgen excess, and the age-related reduction in sex hormone-binding globulin are related to increased NAFLD risk. Moreover, the peri-menopausal changes in body composition and insulin resistance might contribute to the increased NAFLD risk. Whether MHT prevents or improves NAFLD in this population remains an open question. Studies in women with breast cancer treated with tamoxifen or non-steroidal aromatase inhibitors point to their adverse effects on NAFLD development, although a more pronounced effect of tamoxifen is reported. Future studies focusing on the underlying pathogenesis should identify subgroups with the highest risk of NAFLD development and progression into more aggressive forms, as well as elucidate the role of hormone therapies, such as MHT.

Risk of developing metabolic syndrome after gestational diabetes mellitus - a systematic review and meta-analysis.

PURPOSE: A systematic review and meta-analysis were conducted to quantitatively synthesize the current evidence regarding the risk of developing metabolic syndrome (MetS) in women with a personal history of gestational diabetes mellitus (GDM), without pre-existing diabetes, compared with those without a history of GDM. METHODS: Four electronic databases [MEDLINE (via PubMed), Scopus, Cochrane Library, PROSPERO] were searched for relevant literature until July 29th 2020. Cochran's Q test was applied for the assessment of heterogeneity. The random-effects model was applied by calculating the odds ratio (OR) and 95% confidence interval (CI) for each study. Publication bias was estimated with Egger's linear regression test. RESULTS: The results from 23 studies (10,230 pregnant women; 5169 cases, 5061 controls), indicated that women with a history of GDM had a higher risk of developing MetS compared with those without such a history (OR 3.45; 95% CI 2.80-4.25, p < 0.0001). This risk remained higher, independently of maternal age and ethnicity (although the risk was not as high in Asians; OR 2.11; 95% CI 1.27-3.52). The risk of developing MetS was even higher in studies where women with GDM had increased body mass index (BMI) compared with the controls (OR 4.14; 95% CI 3.18-5.38). CONCLUSIONS: The risk for developing MetS following delivery is higher in women with a history of GDM compared with women without such a history. Timely recognition and appropriate intervention are critical to halt progression to MetS and its associated morbidity.

Efficacy of parathyroidectomy compared with active surveillance in patients with mild asymptomatic primary hyperparathyroidism: a systematic review and meta-analysis of randomized-controlled studies.

OBJECTIVE: Parathyroidectomy (PTx) has an established benefit in patients with symptomatic primary hyperparathyroidism (PHPT). However, its efficacy in mild asymptomatic PHPT has not been proven. This study aimed to systematically review and meta-analyze the best available evidence from randomized-controlled trials comparing the efficacy of PTx over conservative management (non-PTx) on skeletal outcomes [fractures and bone mineral density (BMD)], nephrolithiasis risk and quality of life (QoL) in patients with mild asymptomatic PHPT. METHODS: A comprehensive literature search was conducted in PubMed, Scopus and Cochrane databases, from conception to February 23, 2020. Data were extracted from the studies that fulfilled the eligibility criteria and were synthesized quantitatively (fixed or random effects model) as relative risks and percentage mean differences (MD) with 95% confidence intervals (CI). I2 index was employed for heterogeneity. RESULTS: Four studies were included in the meta-analysis. There was no difference in fracture risk between PTx and active surveillance. The PTx group demonstrated higher BMD [MD 3.55% (95% CI 1.81, 5.29) in lumbar spine and 3.44% (95% CI 1.39, 5.49) in total hip, without difference in femoral neck and forearm] and lower calcium concentrations (MD - 13.26%, 95% CI - 7.10, - 19.43) compared with the non-PTx group. No difference was observed between groups regarding nephrolithiasis or QoL indices, except for general health (higher in PTx group). CONCLUSIONS: In patients with mild asymptomatic PHPT, PTx increases BMD and reduces serum calcium concentrations. However, its superiority over active surveillance in terms of fracture risk, nephrolithiasis and QoL cannot be supported by current data.

Ovarian tissue cryopreservation and transplantation to delay menopause: facts and fiction.

Ovarian tissue cryopreservation and transplantation (OTCT) is increasingly being used in young cancer patients for fertility restoration and prevention of premature ovarian insufficiency (POI) and has recently been advocated as a method to delay menopause. This is accomplished by cryopreserving ovarian tissue that is excised laparoscopically in thin pieces at a young age. Cryopreserved tissue will be transplanted at menopause, when ovarian function is no longer present. Transplantation may need to be repeated several times to achieve long-term restoration of ovarian function. However, it is unknown whether ovarian grafts result in a normal steroid pulsatile secretion, similar to that present during reproductive years. In addition, it is not known whether the need to restore ovarian activity appears earlier in women who undergo OTCT to delay menopause, although indirect data suggest that this is likely to be true. Until today, no cohort or comparative studies evaluating OTCT as a potential alternative to hormone replacement therapy (HRT) have been published and, thus, there is no evidence to suggest that OTCT is superior to HRT in terms of both efficacy and safety. Given the availability of alternative, established treatments for managing menopausal symptoms, as well as the multiple unanswered questions regarding the method, it is imperative that, before OTCT is regarded as a mainstream technique for management of menopausal symptoms, further evaluation and clinical investigation are undertaken.

EAA clinical practice guidelines-gynecomastia evaluation and management.

BACKGROUND: Gynecomastia (GM) is a benign proliferation of the glandular tissue of the breast in men. It is a frequent condition with a reported prevalence of 32-65%, depending on the age and the criteria used for definition. GM of infancy and puberty are common, benign conditions resolving spontaneously in the majority of cases. GM of adulthood is more prevalent among the elderly and proper investigation may reveal an underlying pathology in 45-50% of cases. OBJECTIVES: The aim was to provide clinical practice guidelines for the evaluation and management of GM. MATERIALS AND METHODS: A literature search of articles in English for the term 'gynecomastia' was conducted. Evidence-based recommendations were developed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system. RESULTS: A set of five statements and fifteen clinical recommendations was formulated. CONCLUSIONS: The purpose of GM assessment should be the detection of underlying pathological conditions, reversible causes (administration/abuse of aggravating substances), and the discrimination from other breast lumps, particularly breast cancer. Assessment should comprise a thorough medical history and physical examination of the breast and genitalia (including testicular ultrasound). A set of laboratory investigations may integrate the evaluation: testosterone (T), estradiol (E2), sex hormone-binding globulin (SHBG), luteinizing hormone (LH), follicular stimulating hormone (FSH), thyroid stimulating hormone (TSH), prolactin, human chorionic gonadotropin (hCG), alpha-fetal protein (AFP), liver and renal function tests. Breast imaging may be used whenever the clinical examination is equivocal. In suspicious lesions, core needle biopsy should be sought directly instead. Watchful waiting is recommended after treatment of underlying pathology or discontinuation of substances associated with GM. T treatment should be offered to men with proven T deficiency. The use of selective estrogen receptor modulators (SERMs), aromatase inhibitors (AIs) and non-aromatizable androgens is not justified in general. Surgical treatment is the therapy of choice for patients with long-lasting GM. SUMMARY OF STATEMENTS (S) AND RECOMMENDATIONS (R): S1. Gynecomastia (GM) is a benign proliferation of glandular tissue of the breast in males. S2. GM of infancy is a common condition that usually resolves spontaneously, typically within the first year of life. S3. GM of puberty is a common condition, affecting approximately 50% of mid-pubertal boys; in more than 90% of cases, it resolves spontaneously within 24 months. S4. The prevalence of GM in adulthood increases with increasing age; proper investigation may reveal an underlying pathology in approximately 45-50% of the cases. S5. Male breast cancer is rare; GM should not be considered a premalignant condition. The following recommendations are divided into 'strong', denoted by the number 1 and associated with the terminology 'we recommend', and 'weak' denoted by the number 2 and associated with the phrase 'we suggest'. The grading of the quality of evidence is denoted as follows: ⊕○○○ for very low-quality evidence; ⊕⊕○○ for low quality; ⊕⊕⊕○ for moderate quality; and ⊕⊕⊕⊕ for high quality. R1. The presence of an underlying pathology should be considered in GM of adulthood. We recommend that the identification of an apparent reason for GM in adulthood, including the use of medication known to be associated with GM, should not preclude a detailed investigation (1 ⊕⊕⊕○). R2. We suggest that the initial screening to rule out lipomastia, obvious breast cancer, or testicular cancer might be performed by a general practitioner or another non-specialist (2 ⊕○○○). R3. We recommend that in those cases where a thorough diagnostic workup is warranted, it should be performed by a specialist (1 ⊕○○○). R4. We recommend that the medical history should include information on the onset and duration of GM, sexual development and function, and administration or abuse of substances associated with GM (1 ⊕⊕⊕○). R5. We recommend that the physical examination should detect signs of under-virilization or systemic disease (1 ⊕⊕⊕⊕). R6. We recommend that breast examination should confirm the presence of palpable glandular tissue to discriminate GM from lipomastia (pseudo-gynecomastia) and rule out the suspicion of malignant breast tumor (1 ⊕⊕⊕⊕). R7. We recommend that the physical examination should include the examination of the genitalia to rule out the presence of a palpable testicular tumor and to detect testicular atrophy (1 ⊕⊕⊕⊕). R8. We recommend that genitalia examination is aided by a testicular ultrasound, as the detection of a testicular tumor by palpation has low sensitivity (1 ⊕⊕○○). R9. We suggest that a set of evaluations may include T, E2 , SHBG, LH, FSH, TSH, prolactin, hCG, AFP, and liver and renal function tests (2 ⊕⊕○○). R10. We suggest that breast imaging may offer assistance, where the clinical examination is equivocal (2 ⊕⊕○○). R11. We suggest that, if the clinical picture is suspicious for a malignant lesion, core needle biopsy should be performed (2 ⊕⊕○○). R12. We recommend watchful waiting after treatment of underlying pathology or discontinuation of the administration/abuse of substances associated with GM (1 ⊕⊕○○). R13. We recommend that T treatment should be offered only to men with proven testosterone deficiency (1 ⊕⊕⊕○). R14. We do not recommend the use of selective estrogen receptor modulators (SERMs), aromatase inhibitors (AIs), or non-aromatizable androgens in the treatment of GM in general (1 ⊕⊕○○). R15. We suggest surgical treatment only for patients with long-lasting GM, which does not regress spontaneously or following medical therapy. The extent and type of surgery depend on the size of breast enlargement, and the amount of adipose tissue (2 ⊕⊕○○).

European Academy of Andrology guideline Management of oligo-astheno-teratozoospermia.

BACKGROUND: Oligo-astheno-teratozoospermia is frequently reported in men from infertile couples. Its etiology remains, in the majority of cases, unknown with a variety of factors to contribute to its pathogenesis. The aim of this European Academy of Andrology guideline was to provide an overview of these factors and to discuss available management options. MATERIALS AND METHODS: PubMed was searched for papers in English for articles with search terms: male infertility and oligo-astheno-teratozoospermia. For evidence-based recommendations, the GRADE system was applied. Issues related to urogenital infections/inflammations have not been included in this document as they will be covered by separate guidelines. RESULTS: For men with oligo-astheno-teratozoospermia, the European Academy of Andrology recommends: A general physical examination to assess signs of hypogonadism. A scrotal physical examination to assess (i) the testes and epididymes for volume and consistency, (ii) deferent ducts for total or partial absence, and (iii) occurrence of varicocoele. Performing two semen analyses, according to World Health Organization guidelines to define an oligo-astheno-teratozoospermia. An endocrine evaluation. A scrotal ultrasound as part of routine investigation. Karyotype analysis and assessment of Yq microdeletions in infertile men with a sperm concentration ≤5 × 106 /mL. Cystic fibrosis transmembrane conductance regulator gene evaluation in case of suspicion for incomplete congenital obstruction of the genital tract. Against quitting physical activity to improve the chance of achieving pregnancy. Against androgen replacement therapy to improve the chance of achieving pregnancy. Assisted reproduction techniques to improve the chance of achieving pregnancy, in case other treatment options are not available or not efficient. Androgen replacement therapy in patients with biochemical/clinical signs of hypogonadism, after completion of the fertility treatment. CONCLUSION: These guidelines can be applied in clinical work and indicate future research needs.

European Academy of Andrology guideline Management of oligo­astheno­teratozoospermia

Oligo­astheno­teratozoospermia is frequently reported in men from infertile couples. Its etiology remains, in the majority of cases, unknown with a variety of factors to contribute to its pathogenesis. The aim of this European Academy of Andrology guideline was to provide an overview of these factors and to discuss available management options.

Effects of treatment for psoriasis on circulating levels of leptin, adiponectin and resistin: a systematic review and meta-analysis.

BACKGROUND: Metabolic syndrome, a risk factor of cardiovascular disease, is more common in patients with psoriasis than in the general population. Circulating adipokine concentrations are altered in patients with psoriasis and are suggested to represent the pathophysiological link between psoriatic lesions and metabolic alterations. OBJECTIVES: To perform a systematic review of the literature for studies that investigated possible differences in circulating levels of leptin, adiponectin or resistin in patients with psoriasis before and after any treatment intervention, and to meta-analyse the best evidence available. METHODS: A search was conducted in three databases (PubMed, Central and Embase). Eligible for the review were studies that assessed leptin, adiponectin or resistin concentrations in patients with psoriasis before and after any topical or systemic treatment. RESULTS: After treatment, blood concentrations of leptin were similar to those before treatment [standardized mean difference (SMD) 0·06, 95% confidence interval (CI) -0·09 to 0·20], with no heterogeneity among studies (I2 = 0%, P = 0·88). After treatment, blood concentrations of adiponectin were similar to those before treatment (SMD -0·14, 95% CI -0·34 to 0·05), with significant heterogeneity among studies (I2 = 36·8%, P = 0·032). After treatment, blood concentrations of resistin were significantly lower than those before treatment (SMD 0·50, 95% CI 0·20-0·79), with significant heterogeneity among studies (I2 = 61·4%, P < 0·001). CONCLUSIONS: There is no evidence that treatment for psoriasis modifies leptin and adiponectin concentrations. However, treatment intervention reduces resistin concentrations, a finding that is expected to be of clinical importance.

Effect of endocrine disruptors on male reproduction in humans: why the evidence is still lacking?

The so-called "endocrine disruption hypothesis" suggests that exposures to endocrine disruption (EDs) during fetal, neonatal and adult life may interfere with the development of reproductive organs and alter semen quality and reproductive hormone production. Even though animal studies provide substantial evidence of adverse effects of EDs on male reproductive system, epidemiological studies in humans arrive at conflicting results. The aim of the present study was to systematically review the literature to locate methodological characteristics of the studies that struggle the formation of an association between EDs and human male reproduction. Such characteristics include: (i) definition of the exposed and the non-exposed population, (ii) age, (iii) insufficient control for confounders, (iv) ED assay and threshold, (v) time parameters of ED exposure, and (vi) study outcomes. Additional issues are: (i) the late effect of an early exposure, (ii) the multiple exposure effect, and (iii) the fact the same ED may exhibit different modes of action. Unfortunately, the nature of the field precludes the conduction of randomized-controlled trials, which could result to etiological associations between EDs and human male reproduction. Consequently, there is a great need to conduct well-designed studies of case-control or cohort type to evaluate EDs effects on human male reproductive health, and apply possible measures that could limit dangerous exposures.

Association of follicle-stimulating hormone receptor single nucleotide polymorphisms with fertility in Greek men.

BACKGROUND AND OBJECTIVE: Although several epidemiological studies have been conducted, the impact of follicle-stimulating hormone receptor (FSHR) polymorphisms on male infertility remains unclear. The aim of this study was to investigate the prevalence of specific FSHR single nucleotide polymorphisms (SNPs) in the Greek population and associate the latter with the clinical phenotype. PATIENTS AND METHODS: We enrolled 96 subjects: men with idiopathic non-obstructive azoospermia (n = 78) were compared with a control group of fertile men (n = 18) for SNPs in FSHR positions c.-29, c.566, c.919, and c.2039. The SNP in position 566 (c.566C > T) was assessed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) and the other three SNPs (c.-29G > A, c.919A > G, c.2039A > G) with single-strand conformation polymorphism (SSCP); all of them were validated with DNA sequence. RESULTS: No polymorphisms were detected in positions c.-29 and c.919 (c.-29G > A, c.919A > G). The heterozygous SNP (AG) at position 2039 was associated with different size of the right testis (p = 0.008). There was no association between the c.566C > T SNPs polymorphism and hormonal or semen parameters. The combination SNP 2039 AA with 566 CT revealed significant association with FSH and LH concentrations. CONCLUSIONS: FSHR SNPs at positions c.-29, c.566, c.919, and c.2039 (c.-29G > A, c.566C > T, c.919A > G, c.2039A > G) do not appear to play specific roles in male infertility. Larger studies are needed to confirm these results.

Soluble receptor for advanced glycation end products in male infertility.

BACKGROUND: Soluble receptor of advanced glycation end-products (sRAGE) is widely expressed in various organs including male genital tract and spermatozoa. Their regulation depends on many simultaneous conditions that may occur. Male fertility is a multifactorial condition which is influenced by various parameters, some of which are detrimental to the spermatozoa. The aim of this study was to detect possible differences in sRAGE concentrations between serum and seminal plasma of infertile men, compared to fertile men population. METHODS: Seventy-five men were included in the study and divided into three groups: a group of fertile controls (age 34.8 ± 4.6 years, n =12) and two groups of men from infertile couples (age 36.1 ± 5.2 years) with normal (NS, n =10) and abnormal (AS, n =53) semen parameters, respectively. sRAGE was measured by ELISA in serum, and seminal plasma samples of all participants and biochemical, hormonal examinations, as well as anthropometric characteristics, were co-evaluated. Data were statistically analyzed using the chi-square test and the independent samples t-test. A two-tailed p <0.05 was considered significant. RESULTS: Serum sRAGE levels of fertile men were higher than those of men of infertile couples with AS or NS semen parameters (2,061 ± 884 pg/ml vs 1,673 ± 613 pg/ml and 1,411 ± 405 pg/ml, respectively; p <0.058). Seminal plasma sRAGE levels in fertile men were similar to the ones measured in both groups of men from infertile couples AS and NS (327 ± 81 pg/ml vs 322 ± 162 - 413 ± 207 pg/ml; p =0.197). Interestingly, the seminal plasma sRAGE levels in those three groups were significantly lower than the corresponding serum sRAGE levels (p <0.001). CONCLUSION: Serum and seminal plasma sRAGE concentrations seem to show variations worth considering between fertile and infertile men. Moreover, further research is required to elucidate the role of the sRAGEs and oxidative stress in male infertility. HIPPOKRATIA 2017, 21(1): 19-24.

Ultraviolet radiation and effects on humans: the paradigm of maternal vitamin D production during pregnancy.

Current evidence indicates that neonates born of mothers with vitamin D deficiency during pregnancy have greater risk for developing hypocalcemia, rickets and extra-skeletal disorders. Despite the classic knowledge that ultraviolet-B (UVB) exposure is the most efficient way for a future mother to obtain optimal vitamin D concentrations, no current consensus or clinical recommendations exist regarding the duration and timing of UVB exposure for pregnant women. This article offers a narrative review of available data regarding how UVB exposure affects maternal vitamin D production during pregnancy, along with a discourse on clinical implications of this public health issue. Future studies would benefit from adopting UVB exposure estimates to recommend appropriate UVB exposure to pregnant women. Doing so could provide a more holistic and practical approach in managing maternal hypovitaminosis D during pregnancy.

Serum leptin, adiponectin and ghrelin concentrations in post-menopausal women: Is there an association with bone mineral density?

OBJECTIVE: Adipokines and ghrelin exert well-documented effects on energy expenditure and glucose metabolism. Experimental data also support a role in bone metabolism, although data from clinical studies are conflicting. The purpose of this cross-sectional study was to investigate the association of serum concentrations of leptin, adiponectin and ghrelin with bone mineral density (BMD) in post-menopausal women. METHODS: BMD in lumbar spine and femoral neck, and circulating leptin, adiponectin and ghrelin concentrations were measured in 110 healthy post-menopausal women. Patients with secondary causes of osteoporosis were excluded. RESULTS: Osteoporosis was diagnosed in 30 (27%) women and osteopenia in 54 (49%). Serum leptin concentrations were positively correlated with both lumbar spine (r=0.343, p<0.01) and femoral neck BMD (r=0.370, p<0.01). Adiponectin concentrations were negatively associated with BMD at both sites (r=-0.321, p<0.01 and r=-0.448, p<0.01 respectively). No significant correlation between ghrelin concentrations and BMD was found. Osteoporotic women had lower body weight, body mass index (BMI) and leptin concentrations, but higher adiponectin concentrations compared with non-osteoporotic women. In multivariate stepwise regression analysis, the association of adiponectin concentrations with BMD remained significant only for femoral neck, after adjustment for body weight or BMI. CONCLUSIONS: An inverse association between adiponectin and femoral neck BMD was found in post-menopausal women, independently of body weight. The positive association between leptin and BMD was dependent on body weight, whereas no effect of ghrelin on BMD was evident.

Consequences of hyperthyroidism in male and female fertility: pathophysiology and current management.

Thyroid hormone acts on the oocytes, sperm and embryo during fertilization, implantation and placentation. Both hypothyroidism and hyperthyroidism may influence fertility. However, evidence of the association of hyperthyroidism with infertility is scarce and sometimes conflicting. Thyroid hormone influences human reproduction via a variety of mechanisms at both the central and the peripheral level. Infertility may occur in hyperthyroid men and women, but it is usually reversible upon restoration of euthyroidism. This review aims to summarize the available data on the association of hyperthyroidism and infertility in both men and women and to provide practical suggestions for the management of these patients.

Vitamin D and gonadal function in men: a potential inverse U-shaped association?

Accumulating evidence from animal and human studies suggests that vitamin D, apart from its regulatory effects on musculoskeletal health, is involved in reproductive function in both genders. The basis of the interplay between vitamin D and reproduction lays on the presence of both vitamin D receptor (VDR) and 1α-hydroxylase (CYP27B1) enzyme in reproductive organs. In males, VDR are present in testis, epididymis, prostate, and seminal vesicles. In Sertoli cells, whose secretory activities are ion channel-dependent, vitamin D has been shown to stimulate calcium uptake through a nuclear receptor activity. Epidemiological studies support a positive association between serum 25-hydroxy-vitamin D [25(OH)D] concentrations and sperm motility in both fertile and infertile men In addition, large multi-center, cross-sectional studies from Europe and USA have shown positive, linear association between 25(OH)D and androgen concentrations. On the contrary, there are studies that support an inverse U-shaped association, that is, men with both low and high 25(OH)D concentrations demonstrate poorer gonadal function compared with those with intermediate concentrations. Given the rapid increase in over-the-counter use of vitamin D supplements by men that anticipate advantageous health outcomes, the aim of the present commentary is to provide an overview of the studies that present either U-shaped or linear association between 25(OH)D concentrations and male gonadal function.

Hypovitaminosis D in pregnancy in the Mediterranean region: a systematic review.

Despite high levels of sunshine, maternal hypovitaminosis D during pregnancy is prevalent in the Mediterranean region. The aim of this study is to systematically review trials that investigated vitamin D concentrations during pregnancy in this region, in order to determine predictors of hypovitaminosis D and explain this phenomenon. After applying inclusion/exclusion criteria, 15 studies were entered into the systematic review involving 2649 pregnant women and 820 neonates. The main outcome was maternal vitamin D status, assessed by serum 25-hydroxy-vitamin D (25(OH)D) concentrations. Possible predictors of the outcome included maternal age, body mass index (BMI), race, socioeconomic status, skin type, gestational age, sun exposure, calcium and vitamin D intake and supplementation, smoking status, parity and season of delivery. Studies differed widely in vitamin D deficiency criteria, method of measurement and outcomes. The prevalence of vitamin D insufficiency ranges from 9.3 to 41.4%, whereas that of vitamin D deficiency from 22.7 to 90.3%. A positive association with 25(OH)D concentrations exists for light skin color, white race, uncovered dressing pattern, maternal vitamin D supplementation and season of gestation (spring/summer). An inverse association exists for BMI and gestational age, whereas data for smoking and socioeconomic status are controversial. We concluded that vitamin D deficiency in pregnancy seems to be quite common, even in the Mediterranean region. Racial, social and cultural habits, as well as the absence of preventive supplementation/dietary strategies, seem to negate the benefits of sun exposure.

Vitamin D during pregnancy: why observational studies suggest deficiency and interventional studies show no improvement in clinical outcomes? A narrative review.

A considerable number of studies have examined vitamin D status during pregnancy. Although data from observational studies denote vitamin D hypovitaminosis (deficiency or insufficiency) during pregnancy is associated with a plethora of adverse maternal and neonatal outcomes, data from interventional (supplementation) trials fail to reveal a significant impact on maternal and offspring health. The aim of this narrative review was to critically appraise the methodology of the most representative published randomized controlled trials in an attempt to explain the difference between observational and supplementation results. We found that this difference could be attributed to a variety of factors, namely: (i) study design (lack of a specific outcome in conjunction with timing of supplementation, enrolment of participants with heterogeneous vitamin D status); (ii) pitfalls in the interpretation of vitamin D equilibrium (lack of determination of plasma half-life); (iii) supplementation regimen (administration of a wide range of regimens, in terms of dose, bolus and form); (iv) geographical characteristics (vitamin D needs could vary significantly within a country, particularly in areas with a wide range of latitude gradient); (v) adaptations of vitamin D metabolism during pregnancy (vitamin D and calcium equilibrium are changed during pregnancy compared with the non-pregnant state) and (vi) supplementation of populations with low baseline 25(OH)D values would likely manifest beneficial effects. All these parameters should be taken into consideration in the design of future vitamin D supplementation trials.

Vitamin D status during pregnancy: time for a more unified approach beyond borders?

Maternal hypovitaminosis D during pregnancy has been associated with a plethora of adverse health effects on the offspring. Maternal vitamin D status during pregnancy is affected by local climatic conditions. The aim of this article was to report on difficulties related to the heterogeneity of studies available in current literature on vitamin D status during pregnancy and discuss the incorporation of geophysical data in future studies, in an attempt to optimize their design and facilitate their interpretation. We focused on current vitamin D trials during pregnancy and their association with local regional climatic condition in geographical regions such as the Mediterranean basin based on our perspective on the field. Conduction of studies from areas with similar geophysical conditions is necessary, in order to extend our knowledge with respect to the question of which populations and under which circumstances would benefit most from vitamin D supplementation. Future vitamin D studies could benefit from the adoption of a unified concept minimizing these variations by selecting populations residing in areas with similar geophysical conditions adjusting also for their social and dietary habits.

Complex association between body weight and fracture risk in postmenopausal women.

Osteoporosis is a common disease, characterized by low bone mass with micro-architectural disruption and skeletal fragility, resulting in an increased risk of fracture. A substantial number of studies has examined the possible relationship between body weight, bone mineral density and fracture risk in post-menopausal women, with the majority of them concluding that low body weight correlates with increased risk of fracture, especially hip fracture. Controversies about the potential protective effect of obesity on osteoporosis and consequent fracture risk still exist. Several recent studies question the concept that obesity exerts a protective effect against fractures, suggesting that it stands as a risk factor for fractures at specific skeletal sites, such as upper arm. The association between body weight and fracture risk is complex, differs across skeletal sites and body mass index, and is modified by the interaction between body weight and bone mineral density. Some potential explanations that link obesity with increased fracture risk may be the pattern of falls and impaired mobility in obese individuals, comorbidities, such as asthma, diabetes and early menopause, as well as, increased parathyroid hormone and reduced 25-hydroxy-vitamin D concentrations.