Mikiko Watanabe

BMI and BMD: The Potential Interplay between Obesity and Bone Fragility

Recent evidence demonstrating an increased fracture risk among obese individuals suggests that adipose tissue may negatively impact bone health, challenging the traditional paradigm of fat mass playing a protective role towards bone health. White adipose tissue, far from being a mere energy depot, is a dynamic tissue actively implicated in metabolic reactions, and in fact secretes several hormones called adipokines and inflammatory factors that may in turn promote bone resorption. More specifically, Visceral Adipose Tissue (VAT) may potentially prove detrimental. It is widely acknowledged that obesity is positively associated to many chronic disorders such as metabolic syndrome, dyslipidemia and type 2 diabetes, conditions that could themselves affect bone health. Although aging is largely known to decrease bone strength, little is yet known on the mechanisms via which obesity and its comorbidities may contribute to such damage. Given the exponentially growing obesity rate in recent years and the increased life expectancy of western countries it appears of utmost importance to timely focus on this topic.

Obstructive sleep apnea and bone mineral density in obese patients

Context Obesity and its co-morbidities may adversely affect bone mineral density (BMD). Obstructive sleep apnea (OSA) is a major complication of obesity. To date, the effects of OSA on BMD in obese patients have been poorly studied. Objective To examine whether the severity of OSA independently correlates with BMD in obese patients. Methods One hundred and fifteen obese subjects with OSA (Apnea/Hypopnea Index [AHI] ≥5 events per hour) were included in the study. BMD was measured at lumbar spine, total hip, and femoral neck by dual energy X-ray absorptiometry. Body mass index, lean mass, and representative measures of metabolic syndrome (waist circumference, fasting plasma glucose, blood pressure, HDL-cholesterol, triglycerides) and inflammation (ESR, CRP, fibrinogen) were also evaluated. Results BMD did not differ among obese individuals regardless of OSA severity. Correlation coefficient analysis for all the covariates showed a lack of association between AHI and BMD that was strongly influenced by age and weight. Conclusion Our study does not support an independent association between AHI and BMD in obese patients. Controlled studies involving a greater number of patients are warranted.

Vitamin K and osteoporosis: Myth or reality?

Vitamin K is a liposoluble vitamin. The predominant dietary form, phylloquinone or vitamin K1, is found in plants and green vegetables; whereas menaquinone, or vitamin K2, is endogenously synthesized by intestinal bacteria and includes several subtypes that differ in side chain length. Aside from its established role in blood clotting, several studies now support a critical function of vitamin K in improving bone health. Vitamin K is in fact required for osteocalcin carboxylation that in turn regulates bone mineral accretion; it seems to promote the transition of osteoblasts to osteocytes and also limits the process of osteoclastogenesis. Several observational and interventional studies have examined the relationship between vitamin K and bone metabolism, but findings are conflicting and unclear. This systematic review aims to investigate the impact of vitamin K (plasma levels, dietary intake, and oral supplementation) on bone health with a particular interest in bone remodeling, mineral density and fragility fractures.

Overweight and obese patients with nickel allergy have a worse metabolic profile compared to weight matched non-allergic individuals

Background A lack of balance between energy intake and expenditure due to overeating or reduced physical activity does not seem to explain entirely the obesity epidemic we are facing, and further factors are therefore being evaluated. Nickel (Ni) is a ubiquitous heavy metal implied in several health conditions. Regarding this, the European Food Safety Authority has recently released an alert on the possible deleterious effects of dietary Ni on human health given the current levels of Ni dietary intake in some countries. Pre-clinical studies have also suggested its role as an endocrine disruptor and have linked its exposure to energy metabolism and glucose homeostasis dysregulation. Ni allergy is common in the general population, but preliminary data suggest it being even more widespread among overweight patients. Objectives The aim of this study has been to evaluate the presence of Ni allergy and its association with the metabolic and endocrine profile in overweight and obese individuals. Methods We have evaluated 1128 consecutive overweight and obese outpatients. 784 were suspected of being allergic to Ni and 666 were assessed for it. Presence of Ni allergy and correlation with body mass index (BMI), body composition, metabolic parameters and hormonal levels were evaluated. Results We report that Ni allergy is more frequent in presence of weight excess and is associated with worse metabolic parameters and impaired Growth Hormone secretion. Conclusions We confirm that Ni allergy is more common in obese patients, and we report for the first time its association with worse metabolic parameters and impaired function of the GH-IGF1 axis in human subjects.

Mangosteen Extract Shows a Potent Insulin Sensitizing Effect in Obese Female Patients: A Prospective Randomized Controlled Pilot Study

There is a widely acknowledged association between insulin resistance and obesity/type 2 diabetes (T2DM), and insulin sensitizing treatments have proved effective in preventing diabetes and inducing weight loss. Obesity and T2DM are also associated with increased inflammation. Mangosteen is a tropical tree, whose fruits—known for their antioxidant properties—have been recently suggested having a possible further role in the treatment of obesity and T2DM. The objective of this pilot study has been to evaluate safety and efficacy of treatment with mangosteen extract on insulin resistance, weight management, and inflammatory status in obese female patients with insulin resistance. Twenty-two patients were randomized 1:1 to behavioral therapy alone or behavioral therapy and mangosteen and 20 completed the 26-week study. The mangosteen group reported a significant improvement in insulin sensitivity (homeostatic model assessment-insulin resistance, HOMA-IR −53.22% vs. −15.23%, p = 0.004), and no side effect attributable to treatment was reported. Given the positive preliminary results we report and the excellent safety profile, we suggest a possible supplementary role of mangosteen extracts in the treatment of obesity, insulin resistance, and inflammation.

Testicular histopathology, semen analysis and FSH, predictive value of sperm retrieval: supportive counseling in case of reoperation after testicular sperm extraction (TESE)

BackgroundTo provide indicators for the likelihood of sperm retrieval in patients undergoing testicular sperm extraction is a major issue in the management of male infertility by TESE. The aim of our study was to determine the impact of different parameters, including testicular histopathology, on sperm retrieval in case of reoperation in patients undergoing testicular sperm extraction.MethodsWe retrospectively analyzed 486 patients who underwent sperm extraction for intracytoplasmic sperm injection and testicular biopsy. Histology was classified into: normal spermatogenesis; hypospermatogenesis (reduction in the number of normal spermatogenetic cells); maturation arrest (absence of the later stages of spermatogenesis); and Sertoli cell only (absence of germ cells). Semen analysis and serum FSH, LH and testosterone were measured.ResultsFour hundred thirty patients had non obstructive azoospermia, 53 severe oligozoospermia and 3 necrozoospermia. There were 307 (63%) successful sperm retrieval. Higher testicular volume, lower levels of FSH, and better histological features were predictive for sperm retrieval. The same parameters and younger age were predictive factors for shorter time for sperm recovery. After multivariable analysis, younger age, better semen parameters, better histological features and lower values of FSH remained predictive for shorter time for sperm retrieval while better semen and histology remained predictive factors for successful sperm retrieval. The predictive capacity of a score obtained by summing the points assigned for selected predictors (1 point for Sertoli cell only, 0.33 points for azoospermia, 0.004 points for each FSH mIU/ml) gave an area under the ROC curve of 0.843.ConclusionsThis model can help the practitioner with counseling infertile men by reliably predicting the chance of obtaining spermatozoa with testicular sperm extraction when a repeat attempt is planned.

Interdisciplinary Approach to Obesity

Obesity can nowadays be considered a disease with a multifactorial origin. Genes, socioeconomic status, dietary patterns, and psychological profile are only some of the factors that may lead to excess body weight and its deleterious outcomes. A correct assessment of an obese patient cannot be merely limited to weight evaluation, it must consider other aspects such as, among others, biochemical parameters, clinical conditions, and physical fitness. Given its complexity, it has been demonstrated that a multidisciplinary approach is more effective than a single-clinician one in terms of weight loss and comorbidities improvement. Ideally, an obesity management team should be composed of several health professionals such as endocrinologist, clinical nutritionist, a psychiatrist, a bariatric surgeon, and a physiatrist together with other health professionals (i.e., dietitian, psychologist, physiotherapist, nurse). In order to manage every obese subject in an effective manner, different levels of care should be considered: primary care, outpatient clinics held by a multidisciplinary equipe, day hospital, residential rehabilitation treatment, and hospitalization. Although an interdisciplinary approach is advisable in treating obesity, some disadvantages must be considered. In case of a defective communication among team members, there is a risk of losing the full picture of the patient who in turn could receive conflicting advice from each health professional. Moreover, multidisciplinary approach is much more time-consuming than a diet-only treatment, limiting its accessibility to those whose schedules are very flexible. In conclusion, an interdisciplinary approach is to be considered the treatment of choice in the obese patient, but a lot is still to be improved, especially in terms of health professionals’ education to teamwork.