Age, sex, and grip strength determine architectural bone parameters assessed by peripheral quantitative computed tomography (pQCT) at the human radius

The purpose of this study was to estimate the relation of some noninvasively derived mechanical characteristics of radial bone including architectural parameters for bone strength to grip strength and muscle cross-section. Sixty-three males between 21 and 78yr of age and 101 females between 18 and 80yr of age were measured at the nondominant forearm using peripheral quantitative computed tomography (pQCT). We assessed the integral bone mineral density (BMD(I)) and content (BMC(I)) by pQCT at the distal and at the mid-shaft radius. Integral bone area (Area(I)), cortical thickness (C-th), and a newly proposed index for bone strength; the stress-strain index (SSI) were also calculated. The dynamometrically measured maximum grip strength was taken as a mechanical loading parameter and muscle cross-section as a substitute for it. Sex, grip strength, BMC(I) and BMD(I) (distal radius) were identified in a multiple regression analysis to significantly predict bone strength as expressed by SSI, after adjusting for all other independent variables, including age and sex (p<0.0001). Grip strength was closest related to age, sex, BMD(I) and SSI(p) of the distal radius. The cross-sectional area of muscle was not significantly determining the grip strength within the analysis model. In conclusion, our results suggested that architectural parameters at the distal radius were better related to grip strength than to cross-sectional muscle area in both males and females. Maximum muscle strength as estimated by grip strength might be a stronger determinant of mechanical characteristics of bones as compared with cross-sectional muscle area.     

The influence of auxology and long-term glycemic control on muscle function in children and adolescents with type 1 diabetes mellitus

We intended to investigate in this pilot-study if long-term glycemic control stands in close relationship with muscle function in children and adolescents with type 1 diabetes mellitus (T1DM). Muscle function (MIGF, maximal isometric grip force; PJF, peak jump force; PJP, peak jump power) was investigated in 40 children and adolescents (males 20, females 20; age 13.5-/+2.5 yr) affected with T1DM. Muscular parameters were correlated with anthropometric parameters (age, height, weight) and with glycosylated hemoglobin (HbA1c) of the presence and the past. Standard deviation scores (SDSs) of weight and MIGF indicated significantly higher weight (mean 0.75-/+1.83 (SD)) and lower MIGF (mean -1.06-/+1.76 (SD)) in individuals with T1DM. When the study group was divided into two groups by the criteria that the actual HbA1c (HbA1c0) was lower (N=25) or higher (N=15) than 8.5%, the comparison showed significantly higher muscular parameters (PJF-SDS, PJP-SDS and MIGF-SDS) in individuals with higher HbA1c0. Multiple regression analyses demonstrated that body weight and height primarily predicted muscle force (MIGF, PJF) in T1DM. In conclusion, skeletal growth is an important determinant for the development of muscle function in children and adolescents with T1DM.     

Altered brain-derived neurotrophic factor blood levels and gene variability are associated with anorexia and bulimia

Murine models and association studies in eating disorder (ED) patients have shown a role for the brain-derived neurotrophic factor (BDNF) in eating behavior. Some studies have shown association of BDNF -270C/T single-nucleotide polymorphism (SNP) with bulimia nervosa (BN), while BDNF Val66Met variant has been shown to be associated with both BN and anorexia nervosa (AN). To further test the role of this neurotrophin in humans, we screened 36 SNPs in the BDNF gene and tested for their association with ED and plasma BDNF levels as a quantitative trait. We performed a family-based association study in 106 ED nuclear families and analyzed BDNF blood levels in 110 ED patients and in 50 sib pairs discordant for ED. The rs7124442T/rs11030102C/rs11030119G haplotype was found associated with high BDNF levels (mean BDNF TCG haplotype carriers = 43.6 ng/ml vs. mean others 23.0 ng/ml, P = 0.016) and BN (Z = 2.64; P recessive = 0.008), and the rs7934165A/270T haplotype was associated with AN (Z =-2.64; P additive = 0.008). The comparison of BDNF levels in 50 ED discordant sib pairs showed elevated plasma BDNF levels for the ED group (mean controls = 41.0 vs. mean ED = 52.7; P = 0.004). Our data strongly suggest that altered BDNF levels modulated by BDNF gene variability are associated with the susceptibility to ED, providing physiological evidence that BDNF plays a role in the development of AN and BN, and strongly arguing for its involvement in eating behavior and body weight regulation.     

Observational study of bone accretion during successful weight loss in obese adolescents

Objective: To assess bone mineral content (BMC) among obese adolescents who lose weight during a critical period for bone accretion. Methods and Procedures: Whole body, lumbar spine, lower, and upper limb BMC were measured in 62 obese adolescents who completed an intensive 12‐month weight loss trial. BMC was adjusted for height (z ‐scores) using data from a reference group of 66 adolescents (who were 18% overweight). Results: At baseline, the BMC of the obese group was higher than the reference group. During the 12‐month weight loss program, unadjusted BMC increased among the obese adolescents, despite successful weight loss. After adjustment for height, whole body BMC did not change significantly from baseline to 12 months (mean ± s.d.: 1.08 ± 0.67 to 1.06 ± 0.67, P = 0.7). Region‐specific BMC‐for‐height however decreased for the lower (1.07 ± 0.57 to 0.95 ± 0.59, P < 0.001) and upper (1.29 ± 0.56 to 1.18 ± 0.57, P = 0.01) limbs, but lumbar spine BMC‐for‐height increased (0.14 ± 1.06 to 0.40 ± 0.94, P < 0.001). These changes were largely and independently explained by changes in lean and fat mass. Discussion: This study confirms that obese adolescents have high BMC for height and suggests that, unlike adults, their BMC continues to increase during weight loss and remains higher than the BMC of a reference group. After adjustment for growth‐related changes, lower and upper limb BMC appears to decrease, while lumbar spine BMC appears to increase. These results suggest that to optimize the health benefits of weight loss among obese adolescents, their bone health should be better understood and addressed.     

The effect of measurement time when evaluating static muscle endurance during sustained static maximal gripping

The purpose of this study was to examine the useful measurement time when evaluating static muscle endurance by comparing various parameters during sustained static gripping for 1, 3 and 6 min. Fifteen males (mean +/- SD age 20.8 +/- 1.3 yr, height 172.9 +/- 4.6 cm, body mass 67.7 +/- 5.7 kg) and fifteen females [mean +/- SD age 20.2 +/- 0.9 yr, height 158.5 +/- 3.2 cm, body mass 55.9 +/- 4.6 kg] volunteered to participate in this study. The subjects performed the sustained static maximal grip test with a sagittal and horizontal arm position for 1, 3 and 6 min on different days. Eleven force-time parameters were selected to evaluate static muscle endurance. The trial-to-trial reliability of each measurement time of sustained static maximal gripping was very high (rxy = 0.887-0.981 (1 min), 0.912-0.993 (3 min), 0.901-0.965 (6 min)). The errors of exertion values between trials were very small (below 10%). A significant correlation was found in the following parameters: the final strength and the exponential function between 1 min and 3 min, all parameters except for the time required to reach 80% of maximal grip, the regression coefficient at post-inflection between 3 min and 6 min, and the decreasing rate between all measurement times (1 min, 3 min, and 6 min). Significant differences between the measurement times were found in all parameters except for the time to 60, 70, and 80% force decreases, and the regression coefficient of pre-inflection. There was a tendency that the longer the measurement time, the larger the decreasing force. It is suggested that for the 6 min measurement, the subjects unconsciously restrained the maximal gripping force, influenced by a psychological factor as the pain became greater. The 1 min measurement may evaluate only the remarkable decreasing phase of the decreasing force, and not evaluate the phase of an almost steady state.     

The muscle-bone unit in adulthood: influence of sex, height, age and gynecological history on the bone mineral content and muscle cross-sectional area

Bone and muscle development are both strongly influenced by sex hormones. The purpose of this study was to examine the changes in bone and muscle parameters (bone mineral content - BMC, muscle cross-sectional area - MA) in 130 men aged 31 -60 years, and in 180 pre-menopausal women aged 30-53 years with respect to age, body height and, with the women, their gynecological history (age-at-menarche, number of pregnancies, duration of lactation and use of oral contraception). The study was performed using peripheral quantitative computed tomography (pQCT) at a 65% site of the forearm length. Both BMC and MA were dependent on body height (p<0.0001), but not on age. The BMC/MA ratio was dependent neither on age nor on body height in both genders. MA as well as BMC were found significantly higher in males than in females (p<0.0001 for both variables). We observed a significantly higher BMC/MA ratio in females than in males (p<0.0001). We found no effect either of the analyzed variables of gynecological history on bone/muscle characteristics. The findings highlight the necessity of involving height-adjusted parameters and BMC/MA ratio into bone analysis in adults.     

Adrenal steroid hormones and metaphyseal bone in children

BACKGROUND/OBJECTIVES: The responses of metaphyseal bone tissue to physiological variations of endogenous adrenal steroid hormones during childhood are unclear. Therefore, we studied potential hormonal influences in children before the appearance of pubic hair (onset of pubarche). METHODS: Excretions of major glucocorticoid metabolites (C21), cortisol, sum of adrenarchal dehydroepiandrosterone and its immediate 16-hydroxylated metabolites (DHEA&M), and 5-androstene-3beta,17beta-diol (hermaphrodiol) were analyzed in a cross-sectional study in 24-hour urine samples of 109 healthy boys and girls, aged 6-13 years, using steroid profiling by gas chromatography-mass spectrometry. Total and trabecular volumetric bone mineral densities, bone mineral content (BMC) and bone strength strain index were determined with peripheral quantitative computed tomography at the distal forearm. RESULTS: In multiple regression analyses significant associations with the metaphyseal radius were seen for grip force, age, or BMI depending on gender and bone variable analyzed. DHEA&M did not contribute to the explanation of the variance of any bone variable. However, hermaphrodiol positively explained a significant part of variation of bone mineral densities, and BMC (p < 0.01) in girls. Significantly negative associations with all bone variables were seen in boys for cortisol. CONCLUSIONS: The steroid hormones, cortisol and hermaphrodiol, in their physiological ranges, but not the adrenarche marker DHEA&M, appear to associate with metaphyseal bone in a sex-dependent manner during childhood.     

Protective effect of moderate overweight on bone density of the hip joint in elderly and old Austrians

The effect of weight, classified by body mass index (BMI), on bone mass (BMC) of the whole body and on bone mineral density BMD of the hip joint was analysed in a sample of 120 Austrians of Vienna and surroundings. The 68 females and 52 males of this cross sectional study ranged in age between 60 and 92 years (x = 71.7 +/- 7.7). Age distribution was not significantly different between sexes. The WHO (1997) classification of body mass index (BMI) was used for weight classification, i.e. normal weight (BMI 18.5-24.99) and moderate overweight (BMI 25.0-29.99). Obese subjects (BMI 30+) were not included in this study. Bone mass of the whole body as well as bone density of the hip joint were determined by Dual-energy-X-ray absorptiometry (DEXA) using a hologic 2000 scanner. As expected BMC and BMD values were significantly higher in males than in females. While in both females and males moderately overweight BMD of the hip was significantly higher than in those with normal BMI, statistically significant differences of BMC were restricted to females only. Such positive association between body weight and BMC and BMD is in agreement with previous studies on mature subjects, and menopausal and postmenopausal women in particular. In addition, this study demonstrates corresponding positive associations between moderate overweight and bone mass and -density in the elderly and old aged.     

Effect of Orlistat in Obese Patients with Binge Eating Disorder

Objective: Binge eating disorder represents a significant public health problem, with up to 50% of weight loss program participants displaying this disorder. In previous studies with orlistat, patients with binge eating disorder were excluded. The goal of this study was to assess the efficacy of orlistat in obese patients with binge eating disorder. Research Methods and Procedures: Eighty‐nine patients with clinically diagnosed binge eating disorder and a BMI ≥ 30 kg/m² were randomized in double‐blind fashion to 24 weeks of treatment with 120 mg of orlistat or placebo three times daily, in combination with a mildly reduced‐calorie diet. Results: After 24 weeks, the mean weight loss from baseline for orlistat‐treated patients was significantly greater than for patients receiving placebo (?7.4% vs. ?2.3%; p = 0.0001) (intent‐to‐treat analysis). The overall Eating Disorder Inventory 2 score at week 24 was significantly lower in patients treated with orlistat than in those in the placebo group (p = 0.011) Discussion: Orlistat may be considered as part of the management for patients with obesity and binge eating disorder.     

Age-related changes in hand grip strength among rural and urban Haryanvi Jat females

The aim of this study was to investigate the age-related changes in hand grip strength (both right and left hand) among rural and urban Jat females and its correlation with various anthropometric variables. The present cross-sectional study was based on a sample of 600 Jat females (rural=300, urban=300), ranging in age from 40 to 70 years. Findings indicated that rural and urban Jat females exhibit an age-related decline in the mean values of hand grip strength (both right and left hand). The comparison suggested that rural Jat females had significantly higher overall mean value of hand grip strength (kg) (right hand=20.35 vs 18.87, p<0.001 and left hand=17.05 vs 15.68, p<0.001) than their urban counterparts. Mean values for right hand grip strength were found to be higher than left hand grip strength in rural as well as urban Jat females. Significant and positive correlation coefficients exist between hand grip strength (both right and left hand) and various anthropometric variables (height, weight, body mass index, biceps and triceps skinfold thickness) in both rural and urban Jat females. An age-related decline in manual functioning of rural and urban Jat females may be attributed to behavioral factors (reduced physical activity, sedentary lifestyle) and poor nutrition (deteriorating quality and quantity of food intake with increasing age) associated with the normal aging process.     

Bone mass in young patients with type I diabetes

We measured bone mineral content (BMC) with single photon absorptiometry in two groups of young patients with type I diabetes: the first group (prospective study) consists of 48 patients followed from onset to the third year of diabetes and the second group (cross-sectional study) consists of 66 long-term diabetics. Bone mineral content at onset of disease was lower than normal in only two cases. After 3 years of diabetes no male revealed BMC below the normal range but two females (6.6%) had low BMC values. In our cross-sectional study we found a BMC reduction in 12% of the cases. We did not find a relationship between bone deficit and duration of diabetes, or bone mass values and HbA1.     

Effect of bone mineral density on masticatory performance and efficiency

doi: 10.1111/j.1741‐2358.2010.00414.x Effect of bone mineral density on masticatory performance and efficiency Objective: To evaluate the effect of bone mineral density (BMD) on masticatory performance and efficiency in dentate subjects. Background data: Osteoporosis is the most common disorder of the bone. It causes reduction in BMD of the all the skeletal tissue including jaw bones. It also promotes bone loss in jaw bones. In osteoporosis, a reduction of maximal bite force and greater electromyography activity of masticatory muscles is documented. This may lead to the development of masticatory dysfunction which can be assessed by a chewing test in the form of change in masticatory performance and efficiency. Materials and methods: Sixty subjects with equal numbers of men and women were selected for the study, in which BMD screening (T‐score) was carried out to identify the normal, osteopenic and osteoporotic subjects. Their masticatory performance and efficiency was evaluated by a chewing test (fractional sieving method). Results: A high ‘T’ score was associated with low masticatory efficiency and a low ‘T’ score with high masticatory efficiency. Masticatory performance and efficiency was significantly higher among males as compared to females with similar range of BMD. Conclusion: In both genders, high BMD groups (low ‘T’ score) had a significantly high percentage of masticatory efficiency compared to the low BMD (high ‘T’ score) group.     

Birthweight and sociobiological factors in Ilorin, Nigeria

Social and biological factors influencing birthweight of 3053 Ilorin babies were studied. The mean birth weights were 2.998 kg +/- 0.133 (SD) for males and 2.932 kg +/- 0.154 (SD) for females. Multiple regression analysis showed that maternal weight, height, age, education and ethnicity, and child's sex, significantly affected birthweight of infants. Some quadratic and interaction terms also contributed significantly to the prediction of birthweight. The strategies to control the incidence of low birth weight are discussed.     

Normal bone mineral content in young adults with congenital adrenal hyperplasia due to 21-hydroxylase deficiency

OBJECTIVE: To assess bone mineral content (BMC) and body composition in adolescents and young adults with congenital adrenal hyperplasia. METHODS: BMC, anteroposterior-projected bone area (BA), bone mineral density, and fat mass percentage were determined by dual-energy X-ray absorptiometry in 18 patients aged 18-33 years (8 females and 10 males) with 21-hydroxylase deficiency using a Hologic QDR 1000/W densitometer. RESULTS: BMC and bone mineral density for age were significantly reduced at -1.2 standard deviation scores (SDS; range from -2.8 to +4.1) and -1.1 SDS (range from -3.2 to +2.6), respectively. The BA for height was significantly increased at +1.7 SDS (range from -0.5 to +4.8), and the BMC for BA was normal at 0.3 SDS (range from -2.0 to +3.6). The median final height was significantly reduced at -1.6 SDS (range from -5.6 to +0.3), and the fat mass percentage was significantly increased at +1.5 SDS (range from -1.0 to +5.0). CONCLUSION: Our study population of young adults with 21-hydroxylase deficiency had a short stature and broad bones with a normal BMC and had an increased fat mass percentage.     

中等强度跑台运动预防去卵巢大鼠骨质疏松

目的观察中等强度跑台运动对去卵巢大鼠骨质疏松的预防作用。方法将30只3月龄未经产雌性SD大鼠随机分为假手术、去卵巢静止和去卵巢运动三个组。去卵巢运动组每周进行4次时间45min、速度18m/min、坡度5°的跑台训练。实验结束时,检测血清雌二醇（E2）、碱性磷酸酶（ALP）、抗酒石酸酸性磷酸酶（TRAP）和骨钙素（BGP）水平以及右侧游离股骨和胫骨的骨密度（BMD）和骨矿物含量（BMC）;同时观察左侧股骨远端和胫骨近端组织形态学变化。结果与假手术组比较,去卵巢静止组大鼠血清ALP活性和BGP含量显著升高,血清TRAP活性和E2含量显著下降,股骨近段和远端以及胫骨近端BMD和BMC显著下降,股骨远端和胫骨近端骨小梁断裂增加、数目减少;与去卵巢静止组比较,去卵巢运动组大鼠血清E2和BGP含量显著上升,股骨三个部位以及胫骨近端BMD和BMC显著增加,股骨远端和胫骨近端骨小梁断裂减少、数目增加。结论中等强度跑台运动能增加去卵巢大鼠血清E2和BGP含量,改善去卵巢大鼠骨组织学结构。     

Effect of parity on bone mineral density in female rhesus macaques from Cayo Santiago

This cross-sectional study investigates the relationship between parity, bone mineral density, and spontaneous osteopenia/osteoporosis in a large skeletal population of female rhesus macaques (Macaca mulatta) from the free-ranging colony of Cayo Santiago, Puerto Rico. The sample consists of 119 mature female monkeys aged 4.0-22.2 years at time of death. The data consist of measurements of bone mineral content (BMC) and bone mineral density (BMD), obtained from dual-energy X-ray absorptiometry (DEXA) of the last lumbar vertebra. After controlling for age, there is a significant increase in BMD of the spine with increasing parity (P = 0.0006), up to a parity of 7 offspring. Thus, high parity initially has a positive effect on BMD in female rhesus monkeys, but this positive effect disappears with parities that are greater than 7 offspring. After controlling for parity, however, age has a negative (P = 0.015) effect on BMD, beginning several years after the attainment of peak BMD (age 9.5 years). Thus, it appears that parity initially mitigates the effects of aging, but the positive effect of parity on BMD is eventually overwhelmed by the aging process. Mean BMC and BMD values are higher in parous females compared to nulliparous females in the same age range. Similarly, females with low parity have significantly lower mean BMD values than do age-matched high-parity controls, and the frequency of osteopenia and osteoporosis is greater in low-parity females. Forty-three percent (43%) of the osteopenic/osteoporotic females in the sample are members of the low-parity group, even though it composes only 13% (16/119) of the entire sample. This study demonstrates that the free-ranging female rhesus monkeys from Cayo Santiago are a good nonhuman primate model for the study of bone mineral density, parity, osteopenia, and osteoporosis.     

Adolescents with Type 1 Diabetes – The Impact of Gender,Age, and Health-Related Functioning on Eating Disorder Psychopathology

Objective

To investigate correlates of eating disorder psychopathology in adolescent males and females with type 1 diabetes.

Method

A total of 105 adolescents with type 1 diabetes (42% males), aged 12–20 years, were recruited from the Norwegian Childhood Diabetes Registry in this population-based study. All participants were interviewed with the Child Eating Disorder Examination. Additionally, the Brief Illness Perception Questionnaire, the Adolescent Coping Orientation for Problem Experiences and the Beliefs about Medicines Questionnaire were administered to assess health-related functioning. Clinical data were obtained from the Norwegian Childhood Diabetes Registry.

Results

Significant gender differences were demonstrated in the pattern of correlates of eating disorder pathology. Among females, eating disorder psychopathology was significantly associated with body mass index adjusted for age and gender, age, insulin restriction, coping, illness perceptions, and perceptions of insulin concern. In a regression model, age, illness perceptions, and insulin restriction remained significantly associated with eating disorder psychopathology, explaining 48% of the variance. None of the variables were associated with eating disorder psychopathology among males.

Discussion

Greater clinical awareness of illness perceptions, attitudes toward insulin, and insulin restriction may potentially decrease the risk of developing eating disorders among female adolescents with type 1 diabetes, and the subsequent increased morbidity and mortality associated with comorbid type 1 diabetes and eating disorders.     

Hyperactivity in anorexia nervosa: warming up not just burning-off calories

Excessive physical activity is a common feature in Anorexia Nervosa (AN) that interferes with the recovery process. Animal models have demonstrated that ambient temperature modulates physical activity in semi-starved animals. The aim of the present study was to assess the effect of ambient temperature on physical activity in AN patients in the acute phase of the illness. Thirty-seven patients with AN wore an accelerometer to measure physical activity within the first week of contacting a specialized eating disorder center. Standardized measures of anxiety, depression and eating disorder psychopathology were assessed. Corresponding daily values for ambient temperature were obtained from local meteorological stations. Ambient temperature was negatively correlated with physical activity (p = −.405) and was the only variable that accounted for a significant portion of the variance in physical activity (p = .034). Consistent with recent research with an analogous animal model of the disorder, our findings suggest that ambient temperature is a critical factor contributing to the expression of excessive physical activity levels in AN. Keeping patients warm may prove to be a beneficial treatment option for this symptom.     

Validation of a dual energy X-ray absorptiometer: measurement of bone mass and soft tissue composition

We investigated the reproducibility of total and regional body composition measurements performed on a dual energy X-ray absorptiometer (DXA). A group of 38 women aged 21–81 (mean 52. 4) years was scanned twice with repositioning to determine intra-observer reproducibility of measurements of bone mineral density (BMD, g · cm⁻²), bone mineral content (BMC, g), lean mass (LM, kg) and fat mass (FM, kg) of the total body and of the major subregions of the body. In addition, the ability of the DXA machine to detect changes in LM and FM (simulated by placing 11.1 and 22.3 kg porcine lard on the body of 11 subjects) was examined. Coefficients of variations calculated from the root mean square averages of individual standard deviations were as follows (BMD, BMC, FM, LM): 1.4%, 1.1%, 1.4%, 1.7% (total body), 2.2%, 2.1%,-,- (head), 2.8%, 2.8%, 2.0%, 2.2% (trunk), 3.6%, 3.9%, 4.0%, 4.9% (arms), 2.7%, 1.3%, 2.6%, 2.8% (legs). Percentage fat (%fat) of exogenous lard was 81.3 (SD 3.5)% as assessed by the absorptiometer which corresponded well with the result of chemical analysis (82.8%). Estimated %fat of exogenous lard was not influenced by initial body mass or percentage body fat. Percentages of expected mean values with 11.1 kg lard placed on the body were 99.9 (SD 0.3) for body mass, 100.5 (SD 2.1) for LM, and 99.5 (SD 3.5) for FM. BMD was overestimated by 3.2% (P < 0.005) with 11.1 kg lard on the body. BMD as well as BMC increased significantly with 22.3␣kg lard on the body (P < 0.005). The results showed that BMD, BMC, LM, and FM of the total body were precisely estimated by the DXA machine used. Regional measurements were less precise. Changes in total body soft tissue composition were precisely and accurately estimated. The lard placed on the body falsely affected BMD and BMC measurements. Changes in body mass could have a similar effect. Accepted: 6 January 1997