Eddy Zakhem

Physical performance and trabecular bone score in a group of young Lebanese women.

Recent studies have shown that trabecular bone score (TBS) is related to fractures in elderly subjects (1,2). Furthermore, we have recently shown in a study conducted on 4907 Lebanese women that the correlation between lumbar spine bone mineral density (BMD) and TBS is low (r5 0.39; p! 0.001) suggesting that these two parameters reflect different bone properties (3). Identifying simple determinants of TBS may be useful for the prevention and early detection of osteoporotic fractures. The main aim of this study was to identify the determinants of TBS in a group of young Lebanese women. A total of 26 Lebanese adult women whose ages range between 18 and 28 yr participated in this study.Weight and height were measured, and body mass index (BMI) was calculated. Body composition, lumbar spine (L1eL4) BMD, and TBS were evaluated by dual-energy X-ray absorptiometry (Lunar iDXA, GE Healthcare; Madison, WI). Daily calcium intake (DCI) and daily protein intake (DPI) were evaluated using validated questionnaires. Serum vitamin D was assessed. Maximum oxygen consumption (VO2 max; L/min) was measured while exercising on a bicycle ergometer. Performances in vertical jump, horizontal jump, 3-jump test, 5-jump test, and 1⁄2 squat were also measured as previously described (4). Age, weight, height, BMI, lean mass, fat mass, DCI, DPI, and serum vitamin D were not correlated to TBS. The VO2 max (L/min) and performances in vertical jump, horizontal jump, 3-jump test, 5-jump test, and 1⁄2 squat were positively correlated to TBS ( p! 0.05). To our knowledge, this is the first study to show positive correlations between physical performance variables and TBS in young women. Morphological characteristics (weight, lean mass, and BMI) were not positively correlated to TBS. This result is in accordance with that of our previous study conducted on Lebanese women (3). However, our results showed a positive correlation between VO2 max (L/min) and TBS. This is the first study

Performances in Vertical Jump and Horizontal Jump Tests Are Positive Determinants of Hip Bone Mineral Density in a Group of Young Adult Men

Although osteoporosis is known to mainly affect postmenopausal women, there is enough evidence to support substantial bone losswith aging inmen aswell (1,2). Bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) is the best single predictor of fracture risk in elderly subjects (1,2). Among all fragility fractures, hip fractures are the most important in terms of morbidity andmortality (1,2). Highermortality rates after hip fracture have been reported in men compared with women (3). Peak BMD attained at the third decade of life is a strong predictor of fracture risk later in life (4). An increase in peak BMD of 10% would delay the onset of osteoporosis by 13 yr (4). Long-term practice of weight-bearing physical activities stimulates bone formation and enhances BMD of stressed sites (5,6). According to the mechanostat hypothesis, bones adapt their strength tomechanical loads generated fromvoluntarymechanical usage (7). This has been supported bymany animal-based studies (8,9). In humans, it has been shown that body weight and lean mass are the strongest predictors of BMD in both sexes (10,11). Other human-based studies have shown that BMD is correlated to the performances done in some physical tests (12,13). Identifying simple determinants of BMD may be useful for the prevention and early detection of osteoporosis and/or osteopenia. The aim of this study was to explore the relationships between performances in different physical tests (vertical jump [counter-movement jump], standing long jump test, 3-jump test, and 5-jump test) and BMD of the total hip in a group of young adult men. We hypothesized that the objective measures of muscular strength would be correlated to BMD of the hip because hip BMD is strongly correlated to mechanical factors on one hand and the physical tests, which were used in our study to measure the strength and the power of the lower limbs, on the other hand. Ten healthy Lebanese males whose ages ranged from 18 to 30 yr participated in this study. Weight and height were measured, and body mass index (BMI) was calculated. Daily calcium intake, daily protein intake (DPI), and sleep quality were evaluated using

The Influence of Obesity and Overweight on Hip Bone Mineral Density in Lebanese Women

1. Voelker R. 2012 Escalating obesity rates pose health, budget threats. JAMA 308:1514. 2. Fradkin JE, Roberts BT, Rodgers GP. 2012 What’s preventing us from preventing type 2 diabetes? N Engl J Med 367: 1177e1179. 3. Nasreddine L, Naja F, Chamieh MC, et al. 2012 Trends in overweight and obesity in Lebanon: evidence from two national cross-sectional surveys (1997 and 2009). BMC Public Health 12:798. 4. El Bcheraoui C, Chapuis-Lucciani N. 2008 Obesity in the Lebanese elderly: prevalence, relative risks and anthropometrical measurements. J Med Liban 56:174e180. 5. Reid IR. 2010 Fat and bone. Arch Biochem Biophys 503:20e27. 6. Reid IR. 2002 Relationships among body mass, its components, and bone. Bone 31:547e555.

Maximal Oxygen Consumption and Composite Indices of Femoral Neck Strength in a Group of Young Overweight and Obese Men

Several studies have shown positive associations between anaerobic power and bone strength variables (1–4). However, little is known concerning the relation between aerobic power and bone strength in young adults (5–10). Maximal oxygen uptake (VO2 max) is the maximum rate of oxygen consumption as measured during incremental exercise (5–10).VO2 max is widely accepted as the single best measure of cardiovascular fitness and maximal aerobic power (5–10). VO2 max is expressed either as an absolute rate (liter per minute) or as a relative rate (milliliter per minute per kilogram) (5–10). Bone mineral density (BMD) is generally considered as the best determinant of bone strength (11). However, only 50%–70% of bone strength variability can be explained by BMD (11–13). Hip bone strength is also influenced by other factors such as femoral neck (FN) width and bending strength (11–13).Karlamangla et al (14) have examined the prediction of incident hip fracture risk by composite indices of FN strength (compression strength index [CSI], bending strength index [BSI], and impact strength index [ISI]) constructed from dual-energy X-ray absorptiometry scans of the hip.These indices integrate FN size and body size with bone density (14). CSI, BSI, and ISI reflect the ability of the FN to withstand axial compressive and bending forces and to absorb energy from an impact (14–21).These indices have been shown to improve hip fracture risk and bone strength assessments in the elderly (14–16). In children and young adults, physical activity practice positively influences these indices (18–20). In a recent study, we have shown that obesity is associated with low composite indices of FN strength in young obese men (21).Overweight and obese subjects seem to have low VO2 max (milliliter per minute per kilogram) values (22). However, little is known concerning the relation between maximal oxygen consumption and composite indices of FN strength in young obese adults. The aim of the current study was to explore the relationship between maximal oxygen consumption and composite indices of FN strength in a group of young overweight and obese men. Seventy-three overweight and obese (body mass index > 25 kg/m) young men whose ages ranged from 18 to 35 yr participated in the present study.The 73 participants were recruited from3 private universities located inNorthLebanon. All participants were nonsmokers and had no history ofmajor orthopedic problems or other disorders known to affect bone metabolism or physical tests of the study.Other inclusion criteria included no diagnosis of comorbidities and no history of fracture.An informed written consent was obtained from the participants.The current study was approved by the University of BalamandEthics Committee.Bonemineral content and BMD were determined for each individual by dualenergy X-ray absorptiometry at whole body, total hip, and FN (GE Healthcare, Madison, WI). Composite indices of FN strength (CSI,BSI, and ISI) were calculated as previously described (14). We directly assessed the VO2 max of the participants using a Cosmed Fitmate Pro device (version 2.20, Cosmed, Rome, Italy) while exercising on a bicycle ergometer (Siemens-Elema RE 820; Rodby Elektronik AB, Enhorna, Sweden). A progressive 2-min step protocol (20–30W/step) was used as previously described (23). VO2 max (milliliter per minute per kilogram) was positively correlated to CSI (r = 0.51, p < 0.001), BSI (r = 0.28, p < 0.05), and ISI (r = 0.48, p < 0.001). The positive associations between VO2 max (milliliter per minute per kilogram) and 2 indices (CSI and ISI) remained significant after controlling for body mass index using multiple linear regression models. To our knowledge, this is the first study to show positive associations between maximal oxygen consumption (milliliter per minute per kilogram) and composite indices of FN strength in young overweight and obese men. Enhancing cardiovascular fitness may help to reduce osteoporotic fractures in overweight and obese men.

Trabecular Bone Score in Overweight and Normal-Weight Young Women

The aim of this study was to compare Trabecular Bone Score (TBS) in overweight and normal-weight young women. This study included 14 overweight (BMI > 25 kg/m2) and 42 normal-weight (BMI < 25 kg/m2) young Lebanese women whose ages range from 18 to 32 years. Body composition, Bone Mineral Content (BMC), Bone Mineral Density (BMD), and lumbar spine (L1–L4) TBS were assessed by dual-energy X-ray asborptiometry (DXA). The DXA measurements were completed for the whole body (WB), the lumbar spine (L1–L4), the total hip (TH) and the femoral neck (FN). Physical activity, daily calcium intake, daily protein intake and sleep quality index were evaluated using validated questionnaires. Maximal oxygen consumption (VO2 max in l/mn) was measured whilst exercising on a bicycle ergometer using a specialized device. Weight, height, BMI, lean mass, fat mass, WB BMC, WB BMD, TH BMD and FN BMD were significantly higher in overweight women compared to normal-weight women. Trabecular Bone Score (TBS) was not significantly different between the two groups (overweight and normal-weight). In the whole population (n = 56), weight, height, BMI, lean mass and fat mass were positively correlated to BMC and BMD values but not to TBS values. VO2 max (l/mn) was positively correlated to BMC, BMD and TBS (p < 0.05). This study suggests that being overweight is not associated with higher trabecular bone score values in young women.

Vitamin D Level and Composite Indices of Femoral Neck Strength in a Group of Young Lebanese Women

Low serum vitamin D is associated with low bone mineral density (BMD), which is an important predictor of fracture risk (1–6). However, hypovitaminosis D is a prevalent disorder in the Lebanese population (7–13). BMD is generally considered as the best determinant of bone strength and can therefore practically predict fracture risk (14). However, only 50%–70% of bone strength variability can be explained by BMD (15). Hip bone strength is also influenced by other factors such as femoral neck (FN) width and bending strength (16). Karlamangla et al (17) have examined the prediction of incident hip fracture risk by composite indices of FN strength (compression strength index [CSI], bending strength index [BSI], and impact strength index [ISI]) constructed from dualenergy X-ray absorptiometry (DXA) scans of the hip. These indices integrate FN size and body size with bone density (17). CSI, BSI, and ISI reflect the ability of the FN to withstand axial compressive and bending forces and to absorb energy from an impact (17). These indices have been shown to improve hip fracture risk and bone strength assessments in the elderly (17–19). In children and young adults, physical activity practice positively influences these indices (20–23). In a recent study, we have shown that obesity is associated with low composite indices of FN strength in young obese men (24). The aim of the present study was to explore the relationships between serum vitamin D and composite indices of FN strength in a group of young Lebanese men. A total of 116 young Lebanese men (43 obese, 51 overweight, and 22 normal weight) whose ages ranged from 18 to 35 yr participated in the current study. Normal weight, overweight, and obesity are defined by a body mass index (BMI) between 20.0 and 24.9 kg/m, between 25.0 and 29.9 kg/m, and 30 kg/m or more, respectively. The participants were recruited from 3 private universities located in North Lebanon. All participants were nonsmokers and had no history of major orthopedic problems or other disorders known to affect bone metabolism or physical tests of the study. Other inclusion criteria included no diagnosis of comorbidities and no history of fracture. An informed written consent was obtained from the participants. The study was approved by the University of Balamand Ethics Committee. Bone mineral content and BMD were determined for each individual by DXA at whole body, lumbar spine (L1–L4), total hip, and FN (GE Healthcare, Madison,WI). Body composition and trabecular bone score were also evaluated by DXA. Composite indices of FN strength (CSI, BSI, and ISI) were calculated as previously described (17–19). Serum 25-hydroxyvitamin D level was measured by the Nichols Advantage competitive binding chemiluminescence immunoassay (25). Vitamin D insufficiency is defined as a 25(OH)D concentration of <30 ng/mL (26). The mean serum vitamin D level of the studied population was 27.3 ± 12.4 ng/mL. Overall, 65.6% of the subjects were vitamin D insufficient (serum vitamin D < 30 ng/mL). In the whole population (n = 116), serum vitamin D was negatively correlated to body weight (r = −0.33, p < 0.01), BMI (r = −0.30, p < 0.01), fat mass (r = −0.31, p < 0.01), and fat mass percentage (r = −0.26, p < 0.05), but positively correlated to CSI (r = 0.28,p < 0.01), BSI (r = 0.22, p < 0.05), and ISI (r = 0.19, p < 0.05). Serum vitamin D was not significantly correlated to bone mineral content, BMD, or trabecular bone score values. Vitamin D-sufficient men (n = 40) had a significantly higher CSI than vitamin D-insufficient men (n = 76). Our results are in accordance with those reported by Kim et al (27) in Korean women aged ≥50 years. Given that our study sample included obese, overweight, and normal-weight subjects, future larger studies are necessary to confirm whether the relation between serum vitamin D and CSI is independent of or dependent on BMI. Our study suggests that serum vitamin D is a positive but weak determinant of composite indices of FN strength in young men. To our knowledge, this is the first study to find positive correlations between serum vitamin D and composite indices of FN strength in young men. Optimization of serum vitamin D levels may be associated with greater composite indices of FN strength in young Lebanese men. Our study provides an additional evidence of vitamin D on bone health.

Performance Physique et Densité Minérale Osseuse chez de Jeunes Adultes Libanais

Introduction The aim of this study was to explore the relationships between performances obtained in different physical tests and bone parameters (bone mineral density (BMD) and bone mineral content (BMC)) in a group of young Lebanese adults. Methods One hundred and six young Lebanese adults (45 women and 61 men) whose ages range from 17 to 34 years participated in this study. Weight and height were measured, and body mass index (BMI) was calculated. Daily calcium intake, daily protein intake and physical activity level (h/week) were evaluated using validated questionnaires. The level of physical performance was measured using several physical tests: vertical-jump test, standing long jump test, 3-jumptest, 5-jump-test and 1-RM half-squat. Body composition, bone mineral content (BMC) and BMD at whole body (WB), lumbar spine (L2-L4), total hip (TH) and femoral neck (FN) were measured by dual-energy X-ray absorptiometry (DXA). Results In women, height, lean mass, 1- RM half-squat and performances obtained in three physical tests (vertical jump test, 5-jump-test and 1-RM halfsquat) were positively correlated to BMD and BMC. In men, lean mass and 1-RM half-squat were positively correlated to BMD and BMC. Conclusion This study suggests that lean mass and maximum strength obtained in half-squat are positively correlated to BMD in young adults.

La Qualité du Sommeil Est un Déterminant de la Densité Minérale Osseuse de la Hanche Chez un Groupe de Jeunes Hommes Libanais

L’ostéoporose est un problème majeur de santé publique dans la plupart des pays [1-6]. Cette maladie osseuse fréquente est caractérisée par une densité minérale osseuse (DMO) faible et des détériorations microarchitecturales du tissu osseux induisant une augmentation du risque de fracture au niveau de plusieurs sites osseux [1-6]. Bien que l’ostéoporose soit très fréquente chez les femmes postménopausées, son incidence augmente actuellement chez les hommes âgés du fait de l’augmentation de l’espérance de vie [7-8]. Le pic de masse osseuse est un déterminant important du risque fracturaire plus tard dans la vie [1, 9]. De ce fait, l’augmentation du pic de masse osseuse est une stratégie importante dans le domaine de la prévention de l’ostéoporose [9]. Le pic de masse osseuse ou de DMO est régulé par plusieurs facteurs comme la génétique, les facteurs nutritionnels, les facteurs hormonaux, les facteurs mécaniques et d’autres facteurs [1, 9]. Récemment, Fu et coll. [10] ont rapporté une corrélation négative entre la durée du sommeil (h/jour) et la DMO chez des femmes d’âge moyen et âgées. Ces auteurs ont donc suggéré qu’un sommeil court puisse influencer négativement la masse osseuse et pourrait être un facteur de risque d’ostéoporose [10]. Le but de notre étude était d’explorer la relation entre la qualité du sommeil et la densité minérale osseuse de la hanche chez un groupe de jeunes hommes libanais.

Is Obesity Protective Against Vertebral Deformities in Lebanese Women

Vertebral fractures are well known to be the hallmark of osteoporosis (1e5). Vertebral fractures are very common in aging women and can have serious clinical consequences (1e5). Multiple vertebral fractures are associated with morbidity and mortality (1e5). There is no consensus on the exact definition of a vertebral fracture (5). Vertebral morphometry is a quantitative method to identify vertebral fractures based on the measurement of vertebral heights (5). Obesity seems to be protective against hip fractures in elderly subjects (6,7). However, the relation between obesity and vertebral fractures is controversial and seems to be influenced by several factors such as gender and ethnicity (8e12). Recent epidemiologic studies conducted in Lebanon have shown that the incidence of obesity is increasing in an alarming way (13,14). The aim of this study was to explore the relationship between body mass index (BMI) and prevalence of vertebral deformities (anterior wedging) in 2113 Lebanese women aged from 20 to 90 yr. In total, 2113 Lebanese women (607 obese, 834 overweight, and 672 normal weight) whose ages range from 20 to 90 yr participated in this study. Weight and height were measured, and BMI was calculated. Vertebral deformities (anterior wedging) of T4eL4 were determined by morphometric dual-emission X-ray absorptiometry (GE Healthcare Lunar Prodigy, Madison, WI). We defined a vertebral deformity as a ratio of the anterior to posterior heights of !0.8, representing 20% reduction in the height of the anterior portion of a vertebral body relative to the posterior height of that body. The mean age of participants was 61.2 12.5 yr, and mean BMI was 27.6 5.0. In the whole population, the prevalence of having at least 1 vertebral deformity was 27.9%. The prevalence of having at least 1 vertebral deformity was higher ( p ! 0.001) in obese (30.3%) and overweight women (28.8%) compared with normal weight women (18.4%). After adjusting for age, the prevalence of having at least 1 vertebral deformity was not significantly different among the 3 groups (obese, overweight, and normal weight). Using multiple logistic regression analysis, the prevalence of