G. El-Hajj Fuleihan

Low calcium and vitamin D intake in healthy children and adolescents and their correlates.

Background: Optimal dietary calcium and possibly vitamin D intake throughout childhood and adolescence may enhance bone mineral accrual. Little data on the intake of these nutrients in Mediterranean countries exist, and predictors of their suboptimal intake are not well defined.Objective: To evaluate systematically the effect of gender, lifestyle factors, and socioeconomic status on mean calcium and vitamin D intake in healthy school children and adolescents from Lebanon.Design: A total of 385 students aged 10–16 y were selected from four public and four private schools between Fall 1999 and Spring 2000. Information on calcium and vitamin D intake, through a semiquantitative food frequency questionnaire that was validated against a 7-day daily record, and on socioeconomic and lifestyle factors were obtained.Results: Only 12% of the students met the adequate intake (AI) recommendation of 1300 mg of calcium/day, and only 16% met the AI recommendation of 200 IU of vitamin D/day. Boys had a significantly higher mean daily calcium intake than girls. Socioeconomic status as assessed by childrens pocket money was a predictor of higher calcium and vitamin D intake. Eating breakfast and physical activity were other correlates of daily calcium and vitamin D intake.Conclusions: Only a minority of students in our study met the AI for calcium and vitamin D. Gender, lifestyle factors, and socioeconomic status were significant predictors of calcium and vitamin D intake. Our findings have important implications regarding the institution of dietary public health strategies to promote skeletal health in Mediterranean countries during a critical time for bone mass accrual.

Low peak bone mineral density in healthy lebanese subjects

Osteoporosis is a major public health problem in Western countries and is projected to have a similar impact in the Middle East. It has been suggested that peak bone mineral density (BMD), a major determinant of osteoporotic fractures later in life, may be lower in this part of the world compared with the Western world. However, subjects have not been randomly selected or systematically screened to rule out secondary causes of bone loss. The purpose of this study was to determine peak bone mass and lifestyle risk factors for bone loss in a randomly chosen sample of healthy Lebanese subjects from the greater Beirut area. Subjects 25-35 years of age were randomly selected from greater Beirut, which comprises one third of the Lebanese at large, and studied during the Fall of 1999. BMD was measured at the lumbar spine, hip, forearm, and total body. A questionnaire on lifestyle factors was administered to all subjects. Results were compared with the database of subjects from the USA provided by the manufacturer, and to the NHANES database for the total hip. Two hundred thirteen subjects were studied; 45 subjects rotated at all three centers for cross-calibration purposes. Peak BMD in Lebanese subjects was 0.2-0.9 SD below that of peak BMD in American subjects, depending on skeletal site, gender, and densitometer. These differences persisted after attempting to adjust for body size. Osteoporosis and osteopenia were more prevalent than in healthy young Americans. Height, weight, and total body fat were the most significant correlates of BMD/bone mineral content (BMC), accounting for 0.3-0.7 of the variance in bone mass measurement. Lifestyle factors had a very modest but significant contribution to bone mass variance. This is the first population-based study from the Middle East demonstrating that peak BMD is slightly lower in Lebanese subjects compared as with an established database from the USA. Due to the selection of relatively healthier subjects in our study than in the NHANES study, the actual differences between the two populations may be even greater. The impact of our findings on the epidemiology of osteoporotic fractures in Lebanon remains to be determined.

Special report on the official positions of the International Society for Clinical Densitometry

The International Society for Clinical Densitometry (ISCD) periodically holds Position Development Conferences (PDCs) for the purpose of establishing standards and guidelines for indications, acquisition, and interpretation of bone density tests. Topics are selected for consideration by the ISCD Scientific Advisory Committee, reviewed by scientific working groups, and presented to an international panel of experts. Topic categories addressed to date include indications for bone density testing, selection of reference databases for T-scores and Z-scores, clinical applications for central and peripheral bone densitometry, serial bone density testing, instrument precision assessment, phantom scanning and calibration testing, requirements for a bone density report, nomenclature, and diagnosis of osteoporosis in postmenopausal women, premenopausal women, men, and children. Following an open session for public comment and discussion, the panel convenes for consideration of each topic and makes recommendations for positions to the ISCD Board of Directors. Recommendations that are accepted become the Official Positions of the ISCD. This Special Report summarizes the methodology of the ISCD PDCs and presents selected Official Positions of general interest.

Bone and mineral metabolism in patients undergoing Roux-en-Y gastric bypass

SummaryDespite effective weight reduction, the impact of bariatric surgery on bone is a major concern. Mechanisms include decreased mechanical loading, calcium and vitamin D malabsorption, deficiency in other nutrients, and alterations in fat- and gut-derived hormones. The evidence to support clinical care pathways to prevent bone loss and fractures is at this point weak.IntroductionThere is a growing concern regarding the potential deleterious impact of bariatric surgery on bone metabolism. This comprehensive review addresses this controversial topic.MethodsWe reviewed and analyzed articles evaluating bone metabolism and mechanisms for the ensuing putative bone loss in adult patients exclusively undergoing Roux-en-Y gastric bypass (RYGB) surgery, for the period spanning 1942 till September 2012.ResultsMechanisms identified to contribute to alterations in bone metabolism after bypass surgery include: decreased mechanical loading, calcium and vitamin D malabsorption with secondary hyperparathyroidism, deficiency in other nutrients, in addition to alterations in adipokines, gonadal steroids, and gut-derived hormones favoring bone loss, with the exception of serotonin and glucagon-like peptide-1. The relative contribution of each of these hormones to changes in bone homeostasis after bypass surgery remains undefined. Bone loss reflected by a decline in bone mineral density (BMD) and an increase in bone turnover markers have been reported in many studies, limited for the most part by the exclusive use of dual energy X-ray absorptiometry. Well-designed long-term prospective trials with fractures as an outcome, and studies investigating the magnitude, reversibility, and impact of the observed metabolic changes on fracture outcomes are lacking.ConclusionRobust conclusions regarding bone loss and fracture outcome after RYGB surgery cannot be drawn at this time. Although not evidence based, baseline evaluation and sequential monitoring with measurement of BMD and calciotropic hormones seem appropriate, with adequate calcium and vitamin D replacement. Beneficial interventions remain unclear.

Hip fracture incidence in Lebanon: a national registry-based study with reference to standardized rates worldwide

SummaryCrude incidence rates for hip fractures in individuals aged 50 and above in Lebanon were determined using data from the national hip fracture registry. For the years 2006–2008, crude rates varied between 164 and 188/100,000 for females and between 88 and 106 per 100,000 for males. Using the US 2000 white population as a reference, the calculated age-standardized rates were closest to rates derived for southern Europe.IntroductionOwing to the demographic explosion, it is projected that the rates of hip fractures would increase the most in the Middle East and Asia. Few are the population-based studies investigating the incidence of hip fractures in the region.MethodsUsing the Ministry of Health registry data, this population-based study evaluated the incidence of hip fractures in individuals aged 50 and above in Lebanon for the years 2006, 2007, and 2008.ResultsHip fracture crude incidence rates varied across the years between 164 and 188 per 100,000 for females and between 88 and 106 per 100,000 for males, with a female/male ratio of 1.6–2.1. The overall mean age (SD) for hip fractures was 75.9 (9.2), 76.8 (9.0), and 77.0 (9.9) years in females in 2006, 2007, and 2008, respectively, and 74.4 (11.6), 76.3 (10.3), and 74.0 (12.1) years in males, respectively. Using the US 2000 white population as a reference, the age-standardized rates were 370.4, 335.1, and 329.0 for females and 109.7, 134.1, and 128.7 for males, for the years 2006, 2007, and 2008, respectively.ConclusionsThe hip fracture age-standardized incidence rates in the Lebanese subjects receiving Ministry of Health coverage were lower than those found in northern Europe and the US and closest to rates derived for southern Europe.

Effect of age, gender and calciotropic hormones on the relationship between vitamin D receptor gene polymorphisms and bone mineral density

Background/Objectives:Hypovitaminosis D is a major public health problem worldwide and unexpectedly more so in sunny countries. Vitamin D receptor (VDR) gene is associated with inter-individual variance in bone mineral density (BMD). Studies assessing the effect of VDR gene polymorphisms on BMD yielded conflicting results. The aim of this study was to assess the relationship between VDR polymorphisms and BMD in the Lebanese, across age groups and genders and to assess the effect of PTH and lean mass and vitamin D levels on such relationship.Subjects/Methods:In total, 203 subjects aged 65–85 years and 336 children aged 10–17 years. Polymorphisms in the VDR gene were assessed with the restriction enzymes BsmI, TaqI and ApaI. Bone mineral content, BMD and lean mass were measured using Dual-Energy X-ray Absorptiometry (DXA). The dominant hand strength was measured in children.Results:Heterozygote genotype was the most frequent in both age groups. There was no difference in the frequency distribution of genotypes between the young and the elderly. No relationship between VDR genotypes and lean mass was found in either age group. Heterozygote boys had the lowest parathormone (PTH) and heterozygote elderly women had the highest BMD at the spine and forearm.Conclusions:In the Lebanese, the relationship between VDR polymorphisms and BMD differs by age. Survival does not seem to differ by VDR genotype. However, further studies are needed to assess the effect of VDR gene polymorphisms on mortality per se and time to mortality, not evaluated in this study.

Nutritional Osteomalacia Substantial Clinical Improvement and Gain in Bone Density Posttherapy

A 52-yr-old white female presented with worsening low back and hip pain, associated with lower limb proximal muscle weakness and a waddling gait. Her laboratory evaluation revealed hypocalcemia, hypophosphatemia, a very low 25-hydroxyvitamin D level of less than 5 ng/mL, and a bone mineral density in the osteoporotic range. Her laboratory studies were consistent with osteomalacia, although this diagnosis was not established by histomorphometry. She avoided dairy products, spent little time outdoors, and when she went out, she covered her face, arms, and legs. She was on no medication. Her workup for malabsorption including sprue was negative. She was treated with calcium plus high-dose vitamin D 600,000 IU intramuscularly twice witihin 2 mo and had an impressive clinical improvement. Her difficulty with ambulation improved within 1 wk of start of therapy. Her bone mineral density increased by 40% at the spine and 35% at the hip at 4 mo of therapy, by 63% and 39% at 10 mo, and by 62% and 52% at 15 mo at these sites, respectively. Treatment of osteomalacia is extremely rewarding, with dramtic clinical improvement and normalization of bone mineral density.

Effect of vitamin D replacement on maternal and neonatal outcomes: a randomised controlled trial in pregnant women with hypovitaminosis D. A protocol

Introduction The vitamin D recommended doses during pregnancy differ between societies. The WHO guidelines do not recommend routine prenatal supplementation, but they underscore the fact that women with the lowest levels may benefit most. The effects of routine supplementation during pregnancy on maternal and neonatal clinical outcomes have not been investigated in the Middle East, where hypovitaminosis D is prevalent. Our hypothesis is that in Middle Eastern pregnant women, a vitamin D dose of 3000 IU/day is required to reach a desirable maternal 25-hydroxyvitamin D [25(OH)D] level, and to positively impact infant bone mineral content (BMC). Methods and analysis This is a multicentre blinded randomised controlled trial. Pregnant women presenting to the Obstetrics and Gynaecology clinics will be approached. Eligible women will be randomised to daily equivalent doses of cholecalciferol, 600 IU or 3000 IU, from 15 to 18 weeks gestation until delivery. Maternal 25(OH)D and chemistries will be assessed at study entry, during the third trimester and at delivery. Neonatal anthropometric variables and 25(OH)D level will be measured at birth, and bone and fat mass assessment by dual-energy X-ray absorptiometry scan at 1 month. A sample size of 280 pregnant women is needed to demonstrate a statistically significant difference in the proportion of women reaching a 25(OH)D level ≥50 nmol/L at delivery, and a difference in infant BMC of 6 (10)g, for a 90% power and a 2.5% level of significance. The proportions of women achieving a target 25(OH)D level will be compared between the two arms, using χ2. An independent t test will be used to compare mean infant BMC between the two arms. The primary analysis is an intention-to-treat analysis of unadjusted results. Ethics and dissemination The protocol has been approved by the Institutional Review Board at the American University of Beirut-Lebanon (IM.GEHF.22). The trial results will be published in peer-reviewed medical journals and presented at scientific conferences. Trial registration number NCT02434380.

Diagnosis and management of bone fragility in diabetes: an emerging challenge

Fragility fractures are increasingly recognized as a complication of both type 1 and type 2 diabetes, with fracture risk that increases with disease duration and poor glycemic control. Yet the identification and management of fracture risk in these patients remains challenging. This review explores the clinical characteristics of bone fragility in adults with diabetes and highlights recent studies that have evaluated bone mineral density (BMD), bone microstructure and material properties, biochemical markers, and fracture prediction algorithms (i.e., FRAX) in these patients. It further reviews the impact of diabetes drugs on bone as well as the efficacy of osteoporosis treatments in this population. We finally propose an algorithm for the identification and management of diabetic patients at increased fracture risk.