Gender-related changes in three-dimensional microstructure of trabecular bone at the human proximal tibia with aging

Despite increasing interest in age- and gender-related bone alterations, data on trabecular microstructure at the proximal tibia are scarce. The aim of this study was to identify trabecular microstructural change at the human proximal tibia with age and gender, using micro-computed tomography (micro-CT) and scanning electron microscopy (SEM). Fifty-six proximal tibias from 28 Japanese men and women (57-98 years of age) were used in this study. The subjects were chosen to give an even age and gender distribution. Both women and men were divided into three age groups, middle (57-68 years), old (72-82 years) and elderly (87-98 years) groups. The trabecular bone specimens from the medial compartment of the proximal tibial metaphysis were examined. Trabecular bone mineral density (BMD), bone volume fraction (BV/TV) and trabecular thickness (Tb.Th) decreased between the middle-aged and elderly groups similarly in women and men. However, trabecular number (Tb.N) decreased by 13% between the middle-aged and elderly groups in women and nearly double that in men. As compared with women, men had higher BV/TV and lower trabecular separation (Tb.Sp) in the old age and elderly groups, and higher Tb.N and connectivity density (Conn.D) in the elderly group. Increased trabecular resorbing surfaces, perforated or disconnected trabeculae and microcallus formations were observed with age. These findings indicate that both BMD and BV/TV decreased at the proximal tibia with age similarly for women and men, but significant differences between women and men were observed for some microstructural parameters. These findings illustrate potential mechanisms underlying osteoporotic proximal tibial fracture.     

Effect of low-repetition jump training on bone mineral density in young women.

The hypothesis of the present study was that low-repetition and high-impact training of 10 maximum vertical jumps/day, 3 times/wk would be effective for improving bone mineral density (BMD) in ordinary young women. Thirty-six female college students, with mean age, height, and weight of 20.7+/-0.7 yr, 158.9+/-4.6 cm, and 50.4+/-5.5 kg, respectively, were randomly divided into two groups: jump training and a control group. After the 6 mo of maximum vertical jumping exercise intervention, BMD in the femoral neck region significantly increased in the jump group from the baseline (0.984+/-0.081 vs. 1.010+/-0.080 mg/cm2; P<0.01), although there was no significant change in the control group (0.985+/-0.0143 vs. 0.974+/-0.134 mg/cm2). And also lumbar spine (L2-4) BMD significantly increased in the jump training group from the baseline (0.991+/-0.115 vs. 1.015+/-0.113 mg/cm2; P<0.01), whereas no significant change was observed in the control group (1.007+/-0.113 vs. 1.013+/-0.110 mg/cm2). No significant interactions were observed at other measurement sites, Ward's triangle, greater trochanter, and total hip BMD. Calcium intakes and accelometry-determined physical daily activity showed no significant difference between the two groups. From the results of the present study, low-repetition and high-impact jumps enhanced BMD at the specific bone sites in young women who had almost reached the age of peak bone mass.     

Raloxifene: results from the MORE study

Raloxifene is the first Selective Estrogen Receptor Modulator (SERM) approved for the prevention and treatment of osteoporosis in postmenopausal women. Acting as an estrogen agonist in the skeleton and on lipid metabolism, raloxifene maintains bone mineral density (BMD) and prevents new vertebral fractures while improving the lipid profile in postmenopausal women. In an osteoporosis prevention study, 601 women without osteoporosis, aged 45 to 60 years, were assigned to receive a placebo or raloxifene 30, 60, or 150 mg/day. All women received calcium (400 to 600 mg/day). Raloxifene 60 mg increased BMD by 2.4% at both the lumbar spine and hip compared with the placebo at 36 months. More importantly, however, raloxifene significantly reduced the risk of new vertebral fractures in Multiple Outcomes of Raloxifene Evaluation (MORE), a placebo-controlled, double-blind randomized trial of 7705 postmenopausal women with osteoporosis. The women, with a mean age of 66.5 years, and with hip or spine T-score <-2.5 and/or prevalent vertebral fractures, were assigned to receive either a placebo or 60 mg or 120 mg of raloxifene. All women were provided supplemental calcium (500 mg/day) and vitamin D (400 IU/day). After 36 months, raloxifene 60 mg/day and 120 mg/day, reduced the risk of new vertebral fractures by 55% (RR 0.45, 95% CI 0.3, 0.7; p<0.001), and 40% (RR 0.60, CI 0.4, 0.9) in women without prevalent baseline fractures, respectively; and by 31% (RR 0.7, 95% CI 0.6, 0.9; p<0.001), and 49% (RR 0.5, CI 0.4, 0.6) in women with prevalent baseline fractures compared with the placebo. There was no difference in the proportion of women reporting non-traumatic, non - spine fractures among women receiving raloxifene compared to the placebo-treated women. Compared with placebo, BMD increased after 36 months by 2.1 and 2.6% at the femoral neck and spine, respectively, in the 60mg raloxifene group, and by 2.4 and 2.7% at the femoral neck and spine, respectively, in the 120mg raloxifene group. By 40 months of follow-up, there was a higher rate of deep venous thrombosis (38 cases) and pulmonary embolus (17 cases) in the combined raloxifene groups than in the placebo group (5 and 3 cases,), with a relative risk of 3.1, (CI 1.5-6.2). By 40 months, 54 women had a confirmed diagnosis of breast cancer with a relative risk compared to placebo of 0.35, (CI, 0.21-0.58). Raloxifene therapy for 3 years maintains BMD in healthy postmenopausal women and significantly reduces the risk of new vertebral fractures by about half in postmenopausal women with osteoporosis. Raloxifene also reduces the risk of breast cancer by 65% in postmenopausal women with osteoporosis thus providing a new choice for addressing postmenopausal health concerns.     

Bone loss in the ovariectomized baboon Papio ursinus: densitometry, histomorphometry and biochemistry

To develop a non-human primate model of systemic bone loss after ovariectomy, 24 ovariectomized (OVX) and eight control (non-OVX) female baboons Papio ursinus were investigated over a period of 48 months using bone mineral density (BMD), iliac crest bone histomorphometry, bone turnover markers, and variables of calcium metabolism. Lumbar spine (L1-L4) BMD measured by dual energy X-ray absorptiometry (DXA) decreased in OVX animals in the first 12 months (-7.6%) and showed a slow trend towards recovery after 24 months. Controls showed a slow increase in spinal BMD over 4 years (+9.7%). Total hip BMD decreased slowly up to 48 months in all animals (OVX -12.6%versus controls -10%); this indicated that OVX had a limited effect on total hip BMD. Forearm BMD did not change. The significant decrease in trabecular bone volume (TBV) of the iliac crest from baseline to 12 months was followed by some recovery. Microarchitectural deterioration of trabecular bone in OVX animals was demonstrated by a decline in trabecular number and an increase in trabecular spacing. These changes were also evident on sections of whole vertebrae, proximal femora and iliac crests. Changes in iliac TBV reflected spinal but not hip BMD changes in the OVX animals. Static and dynamic histomorphometric variables indicated that bone turnover was increased for 36 months following OVX. Controls showed no changes in histomorphometric variables. Bone specific alkaline phosphatase (ALPs) in OVX animals remained elevated throughout the study; osteocalcin (OC) was significantly elevated only at 6 and 12 months, and deoxypyridinoline (Pyr-D) was elevated at 12 months but declined after 24 months. ALPs was thus more sensitive to the long-term effects of OVX than were OC or Pyr-D. Controls showed no changes in bone turnover markers. This study showed consistent deleterious changes in lumbar BMD, bone histomorphometry with microarchitectural deterioration together with altered biochemical markers of bone turnover in the first 12 months after OVX. Since these changes resemble those in post-menopausal women, the non-human primate Papio ursinus is suitable for the study of bone loss in post-menopausal women.     

Association of a polymorphism of the CC chemokine receptor-2 gene with bone mineral density

The possible association of the 190G-->A (Val64Ile) polymorphism of the CC chemokine receptor-2 gene (CCR2) with bone mineral density (BMD) was examined in 2215 subjects (1125 men, 1090 women), all of whom were community-dwelling individuals aged 40 to 79 years. Among men aged < 60 years, BMD for the distal radius, lumbar spine, or Ward's triangle was significantly greater in those with the AA genotype than in those with the GG or GA genotypes. For postmenopausal women, BMD for the distal radius or femoral neck was significantly greater in those with the AA genotype than in those with the GG or GA genotypes. In contrast, for men aged > or =60 years and for premenopausal women, BMD was not associated with the CCR2 genotype. These results suggest that CCR2 may be a new candidate for a susceptibility locus for bone mass in middle-aged men and postmenopausal women.     

Receptor activator of NF-[kappa]B ligand arrests bone growth and promotes cortical bone resorption in growing rats.

Receptor activator of NF-kappaB ligand (RANKL), produced by osteoblastic lineage cells and activated T cells, is an essential factor for osteoclast differentiation, activation, and survival. Therefore, RANKL is a focal point of therapies targeting bone diseases where there is an imbalance of bone metabolism in favor of bone resorption. The present study assesses the effects of exogenous RANKL on growing bone. RANKL (100 microg x kg-1x day-1 for 7 days) administered to Sprague-Dawley weanling rats caused major deficits in growth, appearance, and bone mineral densities (BMD). Urinary deoxypyridinoline crosslinks, a measure of bone turnover, were higher in the RANKL-treated rats (P = 0.031), and the bone mineral content was lower (P < 0.001). The final BMD in the RANKL-treated rats was lower (P = 0.039) than in the control rats (19 +/- 7 vs. 38 +/- 5 mg/cm3). Moreover, calculated cortical bone density in each bone slice (total BMD - trabecular BMD) indicated there was only 5% cortical bone remaining in RANKL-treated rats. We conclude that therapies targeting RANKL are likely to have effects on cortical as well as trabecular bone density.     

Resistance exercise as a countermeasure to disuse-induced bone loss.

During spaceflight, skeletal unloading results in loss of bone mineral density (BMD). This occurs primarily in the spine and lower body regions. This loss of skeletal mass could prove hazardous to astronauts on flights of long duration. In this study, intense resistance exercise was used to test whether a training regimen would prevent the loss of BMD that accompanies disuse. Nine subjects (5 men, 4 women) participated in a supine maximal resistance exercise training program during 17 wk of horizontal bed rest. These subjects were compared with 18 control subjects (13 men, 5 women) who followed the same bed rest protocol without exercise. Determination of treatment effect was based on measures of BMD, bone metabolism markers, and calcium balance obtained before, during, and after bed rest. Exercisers and controls had significantly (P < 0.05) different means, represented by the respective following percent changes: lumbar spine BMD, +3% vs. -1%; total hip BMD, +1% vs. -3%; calcaneus BMD, +1% vs. -9%; pelvis BMD, -0.5% vs. -3%; total body BMD, 0% vs. -1%; bone-specific alkaline phosphatase, +64% vs. 0%; alkaline phosphatase, +31% vs. +5%; osteocalcin, +43% vs. +10%; 1,25 dihydroxyvitamin D, +12% vs. -15%; parathyroid hormone intact molecule, +18% vs. -25%; and serum and ionized calcium, -1% vs. +1%. The difference in net calcium balance was also significant (+21 mg/day vs. -199 mg/day, exercise vs. control). The gastrocnemius and soleus muscle volumes decreased significantly in the exercise group, but the loss was significantly less than observed in the control group. The results indicate that resistance exercise had a positive treatment effect and thus might be useful as a countermeasure to prevent the deleterious skeletal changes associated with long-duration spaceflight.     

Validity of hamstring muscle length assessment during the sit-and-reach test using an inclinometer to measure hip joint angle

The aim of this study was twofold: (i) to describe the criterion-related validity of the sit-and-reach test (SRT) using a hand-held inclinometer when assessing hamstring muscle length (HML) when HML is recorded in degrees of hip joint angle (HJA); and (ii) to describe the effect of gender and age on HML in healthy adults during the performance of a SRT. We examined 212 healthy subjects (106 men and 106 women) whose ages ranged from 20 to 79 years. The Pearson-product moment correlation coefficient (r) described the relationship between HJA at the end-point of the SRT and the criterion, supine passive straight-leg raise (PSLR). We conducted a 6 x 2 analysis of variance, where age was stratified on 6 levels of 10-year increments (20-29, 30-39, 40-49, 50-59, 60-69, and 70-79 years of age) and gender was stratified on 2 levels (men and women). There was a statistically significant correlation (r = 0.59, P < 0.01) between performance on the SRT as measured by HJA and the supine PSLR, but the SRT only accounted for 35% of the variability in the PSLR. SRT performance in men (mean +/- SD, 80 +/- 9 degrees) was significantly less (P < 0.001) than in women (mean +/- SD, 92 +/- 10 degrees). Subjects in the 60- to 69- and 70- to 79-year age groups had significantly less (P < 0.05) HJA than those in the 20- to 29-, 30- to 39-, and 40- to 49-year age groups. Using an inclinometer to measure HJA during the SRT is not a valid method for assessing HML in men and women who can independently assume a long-sitting position on a hard surface. Clinicians should recognize there are differences in HML between men and women, and that men and women between 20 to 49 years of age have more HML than their counterparts between ages 60 to 79 years.     

Reduced bone mineral density is not associated with significantly reduced bone quality in men and women practicing long-term calorie restriction with adequate nutrition

Calorie restriction (CR) reduces bone quantity but not bone quality in rodents. Nothing is known regarding the long-term effects of CR with adequate intake of vitamin and minerals on bone quantity and quality in middle-aged lean individuals. In this study, we evaluated body composition, bone mineral density (BMD), and serum markers of bone turnover and inflammation in 32 volunteers who had been eating a CR diet (approximately 35% less calories than controls) for an average of 6.8 ± 5.2 years (mean age 52.7 ± 10.3 years) and 32 age- and sex-matched sedentary controls eating Western diets (WD). In a subgroup of 10 CR and 10 WD volunteers, we also measured trabecular bone (TB) microarchitecture of the distal radius using high-resolution magnetic resonance imaging. We found that the CR volunteers had significantly lower body mass index than the WD volunteers (18.9 ± 1.2 vs. 26.5 ± 2.2 kg m(-2) ; P = 0.0001). BMD of the lumbar spine (0.870 ± 0.11 vs. 1.138 ± 0.12 g cm(-2) , P = 0.0001) and hip (0.806 ± 0.12 vs. 1.047 ± 0.12 g cm(-2) , P = 0.0001) was also lower in the CR than in the WD group. Serum C-terminal telopeptide and bone-specific alkaline phosphatase concentration were similar between groups, while serum C-reactive protein (0.19 ± 0.26 vs. 1.46 ± 1.56 mg L(-1) , P = 0.0001) was lower in the CR group. Trabecular bone microarchitecture parameters such as the erosion index (0.916 ± 0.087 vs. 0.877 ± 0.088; P = 0.739) and surface-to-curve ratio (10.3 ± 1.4 vs. 12.1 ± 2.1, P = 0.440) were not significantly different between groups. These findings suggest that markedly reduced BMD is not associated with significantly reduced bone quality in middle-aged men and women practicing long-term calorie restriction with adequate nutrition.     

Cross sectional and longitudinal study of bone mineral content of the distal forearm in adult premenopausal women

The range of fat corrected distal forearm mineral content (FMC) (at a site which comprises approximately 75% cortical and 25% trabecular bone) and the effect of aging on FMC were determined in normal premenopausal women. In 106 women (mean age 39; range 18-56) the mean FMC was 1.184 (SD 148) g/cm; fat correction increased this to 1.239 (SD 148) g/cm. There were significant correlations between fat corrected FMC and height, weight and BMI (r greater than 0.16; P less than 0.05). In 43 of these women (mean age 35; range 18-51) repeat measurements of FMC were performed. The last measurement was separated from the first by a mean time interval of 27 +/- 3 months. There was no significant change in uncorrected FMC (baseline 1.185 +/- 0.21 g/cm compared with their final measurement 1.182 +/- .020 g/cm; P = 0.51). Fat-corrected FMC (baseline 1.229 +/- .021 g/cm compared with 1.223 +/- .020 g/cm later) tended to decrease although this change was not significant (P = 0.06). Age ranked cusum analysis demonstrated a non-significant fat-corrected rate of change in FMC of -.3% yr in those over 35 years of age (P less than 0.10). This data suggests that if there is any distal forearm bone loss before the menopause it is negligible.     

The effect of primary lack of estrogens and the influence of the age at the beginning of estrogen therapy on bone mineral density in patients with Turner's syndrome

Lumbar spine bone mineral density (BMD) values were measured in women with Turner's syndrome (TS) and the influence of primary ovarian failure as well as the age at the start of estroprogestins (EP) therapy were considered. EP treatment with 2mg of estradiol (E2) and BMD monitoring were started in 72 and finally continued for 5 years in 34 patients with TS, aged 12-38 years, previously not treated with growth hormone or anabolic steroids. The mean total BMD gain (deltaBMD) was 20% and the most significant increase was observed after the first (7.5%) and the second (6.6%) year of the therapy. Before the start and during EP treatment E2 levels were evaluated: they increased from 9.2pg/ml to the values observed in the controls (C) but positive correlation with BMD was not observed. Analysis of TS patients in age brackets (<15 years, 15-20 years, 21-25 years, >25 years) showed that only in the group that started EP treatment before the age of 15 every year significant deltaBMD was observed. The group that started EP therapy after the age of 20 didn't achieve significant deltaBMD. Patients wit TS had significantly higher levels of bone metabolism markers (Ntx and BALP) than the controls and in both groups negative correlation with age was found. On the basis of the results the conclusion was made that in hypoestrogenic women, not exclusively TS, the age when estrogen therapy is started may determine the effects in relation to bone mass. The administered E2 doses may also be important.     

Diabetic Polyneuropathy Relates to Bone Metabolism and Markers of Bone Turnover in Elderly Patients With Type 2 Diabetes: Greater Effects in Male Patients

BackgroundThere is evidence that diabetic polyneuropathy (PNP) is associated with reduced bone mineral density (BMD) in type 1 diabetes but little is known about the impact of diabetic PNP on bone metabolism in type 2 diabetes.ObjectivesThe aim of this study was to evaluate differences in bone metabolism by measuring markers of bone turnover and BMD in men and postmenopausal women with type 2 diabetes and diabetic PNP compared with those without PNP. Gender differences were analyzed for both groups of patients.MethodsOne hundred twenty patients with type 2 diabetes, 68 without PNP (43 men, 25 women, mean age 62 [8] years) and 52 with PNP (28 men, 24 women, mean age 64 [8] years) were studied. Clinical parameters with bone turnover biomarkers such as osteocalcin, bone alkaline phosphatase, procollagen type 1 amino-terminal propeptide, and carboxy-terminal telopeptide of type 1 collagen were measured in all patients. Dual energy x-ray absorptiometry to evaluate BMD was performed in a subgroup of patients.ResultsAfter controlling for age, body mass index, duration of diabetes, smoking, glycosylated hemoglobin, homeostasis model assessment index for insulin resistance, serum C-reactive protein, creatinine, calcium, gamma-glutamyltransferase, parathyroid and sex hormones levels, presence of micro/macrovascular complications, statin- as well as diabetes-related therapies, levels of carboxy-terminal telopeptide of type 1 collagen and procollagen type 1 amino-terminal propeptide were significantly higher among patients with PNP when compared with patients without PNP (P = 0.01 and P = 0.03, respectively). Differences in bone biomarkers were more pronounced among men with diabetes. BMD did not differ significantly between patients with and without PNP, independent of gender.ConclusionsMale patients with PNP exhibit a higher rate of bone turnover than men without PNP. High rate of bone turnover increases the susceptibility for developing osteoporosis. Prevention of diabetic PNP might also reduce the incidence of osteoporosis and fractures in patients with type 2 diabetes.     

Exercise,smoking, and calcium intake during adolescence and early adulthood as determinants of peak bone mass. Cardiovascular Risk in Young Finns Study Group.

OBJECTIVE--To evaluate the contribution to peak bone mass of exercise, smoking, and calcium intake in adolescents and young adults. DESIGN--Prospective cohort study with end point measurement (bone mineral density) after 11 years'' follow up for lifestyle. SETTING--Five university hospital clinics. SUBJECTS--264 (153 females, 111 males) subjects aged 9 to 18 years at the beginning of the follow up and 20 to 29 years at the time of measurement of bone mineral density. MAIN OUTCOME MEASURE--Bone mineral density of lumbar spine and femoral neck by dual energy x ray absorptiometry; measures of physical activity and smoking and estimates of calcium intake repeated three times during follow up. RESULTS--In the groups with the lowest and highest levels of exercise the femoral bone mineral densities (adjusted for age and weight) were 0.918 and 0.988 g/cm2 for women (P = 0.015, analysis of covariance) and 0.943 and 1.042 g/cm2 for men (P = 0.005), respectively; at the lumbar spine the respective values were 1.045 and 1.131 (P = 0.005) for men. In men the femoral bone mineral densities (adjusted for age, weight, and exercise) were 1.022 and 0.923 g/cm2 for the groups with the lowest and highest values of smoking index (P = 0.054, analysis of covariance). In women the adjusted femoral bone mineral density increased by 4.7% together with increasing calcium intake (P = 0.089, analysis of covariance). In multiple regression analysis on bone mineral density of the femoral neck, weight, exercise, age, and smoking were independent predictors for men; with weight, exercise, and age for women. These predictors together explained 38% of the variance in bone mineral density in women and 46% in men. At the lumbar spine, weight, smoking, and exercise were predictors for men; and only weight for women. CONCLUSIONS--Regular exercise and not smoking is important in achieving maximal peak bone mass in adolescents and young adults.     

Controlled trial of the effects of milk basic protein (MBP) supplementation on bone metabolism in healthy adult women

Milk has more beneficial effects on bone health compared to other food sources. Recent in vitro and in vivo studies showed that milk whey protein, especially its basic protein fraction, contains several components capable of both promoting bone formation and inhibiting bone resorption. However, the effects of milk basic protein (MBP) on bone metabolism of humans are not known. The object of this study was to examine the effects of MBP on bone metabolism of healthy adult women. Thirty-three normal healthy women were randomly assigned to treatment with either placebo or MBP (40 mg per day) for six months. The bone mineral density (BMD) of the left calcaneus of each subject was measured at the beginning of the study and after six months of treatment, by dual-energy x-ray absorptiometry. Serum and urine indices of bone metabolism were measured at the base line, three-month intervals, and the end of the study. Daily intake of nutrients was monitored by a three-day food record made at three and six months. The mean (+/- SD) rate of left calcaneus BMD gain of women in the MBP group (3.42 +/- 2.05%) was significantly higher than that of women in the placebo group (2.01 +/- 1.75%, P = 0.042). As compared with the placebo group, urinary cross-linked N-teleopeptides of type-I collagen/creatinine and deoxypyridinoline/creatinine were significantly decreased in the MBP group (p < 0.05), while no significant differences between the two groups were observed in serum osteocalcin and bone-specific alkaline phosphatase concentrations. A daily MBP supplementation of 40 mg in healthy adult women can significantly increase their BMD independent of dietary intake of minerals and vitamins. This increase in BMD might be primarily mediated through inhibition of osteoclast-mediated bone resorption by the MBP supplementation.     

Association of a -1997G-->T polymorphism of the collagen Ialpha1 gene with bone mineral density in postmenopausal Japanese women

Genetic variants that affect collagen Ialpha1 metabolism may be important in the development of osteoporosis or osteoporotic fractures. A -1997G-->T polymorphism in the promoter of the collagen Ialpha1 gene (COL1A1) was shown to be associated with bone mineral density (BMD) for the lumbar spine in postmenopausal Spanish women. The relation of this polymorphism to BMD in Japanese women or men has now been examined in a population-based study. The subjects (1,110 women, 1,126 men) were 40 to 79 years of age and were randomly recruited for a population-based prospective cohort study of aging and age-related diseases. BMD for the lumbar spine, right femoral neck, right trochanter, and right Ward's triangle was measured using dual-energy x-ray absorptiometry. Genotypes for the -1997G-->T polymorphism of COL1A1 were determined with a fluorescence-based allele-specific DNA primer assay system. When all women were analyzed together, BMD for the lumbar spine and trochanter was significantly lower in subjects with the COL1A1 *G/*G genotype than in those in the combined group of COL1A1 *G/*T and COL1A1 *T/*T genotypes. When postmenopausal women were analyzed separately, BMD for the femoral neck and trochanter was also significantly lower in those with the COL1A1 *G/*G genotype than in those with the COL1A1 *G/*T genotype or those in the combined group of COL1A1*G/*T and COL1A1 *T/*T genotypes. BMD was not associated with -1997G-->T genotype in premenopausal women or in men. Multivariate regression analysis revealed that -1997G-->T genotype affected BMD at various sites with a variance of 0.46-0.62% for all women and 0.61-1.01% for postmenopausal women. The -1997G-->T genotype was not related to the serum concentration of osteocalcin, the serum activity of bone-specific alkaline phosphatase, or the urinary excretion of deoxypyridinoline or cross-linked N-telopeptides of type I collagen in men or in premenopausal or postmenopausal women. These results suggest that COL1A1 is a susceptibility locus for reduced BMD in postmenopausal Japanese women.     

Caries and periodontal disease of the elderly in Pomerania, Germany: results of the Study of Health in Pomerania

Objective: The aim of this study was to describe the oral health status of older adults living in north‐eastern Germany. Materials and Methods: Representative samples of adults aged 60 years or older were examined as part of Study of the Health in Pomerania, a cross‐sectional, population‐based study. Data on 1446 subjects aged 60–79 years were evaluated for coronal caries using the decayed/missing/filled teeth (DMFT) index, root caries using the root caries index (RCI), calculus, plaque, bleeding on probing, pocket depth and attachment loss. Results: The prevalence of edentulousness varied from 16% in the 60–65‐year‐old group to 30% in the 75–79‐year‐old group, whereas the median number of remaining natural teeth per subject varied from 14 in the youngest age group (60–65 years) to one in the oldest (75–79 years). Among subjects aged 60–69 years, a quarter (26%) of the teeth examined had coronal restoration against 17% in the oldest age group (70–79 years). Coronal caries was found in 2% of the teeth in both age groups. Among teeth with gingival recession, 6% had fillings on root surfaces and 2% had root caries, irrespective of age. In all, 11% of the subjects had at least one untreated coronal lesion and 27% had at least one untreated root caries lesion. Plaque score, calculus score and bleeding on probing were higher in the oldest age group (70–79 years). The prevalence of periodontal disease expressed as the presence of at least one periodontal pocket of 4 mm and more, was higher in men and among the younger subjects (men aged 60–69 years: 85% vs. 71% in 70–79‐year‐old men; women aged 60–69 years: 71% vs. 62% in 70–79‐year‐olds). The prevalence of attachment loss of 3 mm or more followed a similar pattern. Conclusions: It seems therefore that in this population, the major oral health concern is related to caries and the small number of teeth retained among the dentate subjects.     

Compensatory muscle fiber hypertrophy in elderly men.

Muscle strength and muscle morphology have been studied three times during a period of 11 yr in nine elderly men. On the last occasion the average age was 80.4 (range 79-82) yr. Body cell mass decreased by 6% and muscle strength for knee extension, measured by means of isometric and concentric isokinetic (30-60 degrees/s) recordings, declined by 25-35% over the 11-yr period. Between 76 and 80 yr of age only the isokinetic strength for 30 degrees/s decreased significantly. Muscle fiber composition in the vastus lateralis did not change between 69 and 76 yr of age, but there was a significant reduction in the proportion of type IIb fibers from 76 to 80 yr. The decrease in type II fiber areas was not significant between 69 and 76 yr of age (as in a larger sample from the same population), but a significant increase in both type I and type II fiber areas was recorded from 76 to 80 yr of age and biceps brachii showed similar tendencies. In the same period, the enzymatic activities of myokinase and lactate dehydrogenase subsided in the vastus lateralis, but there was no change for triose phosphate dehydrogenase, 3-hydroxy-CoA-dehydrogenase, and citrate synthase. The muscle fiber hypertrophy in this group of elderly men with maintained physical activity between 76 and 80 yr of age is interpreted as a compensatory adaptation for the loss of motor units. In addition, the adaptation with respect to oxidative capacities seems to be maintained at this age.     

Glucocorticosteroid-induced osteoporosis in adult primiparous Göttingen miniature pigs: effects on bone mineral and mineral metabolism

Information on the pathophysiology of glucocorticoid-induced osteoporosis (GIO) is limited, since its clinical picture often reflects a combined effect of glucocorticoids (GC) and the treated systemic disease (i.e., inflammation and immobility). In 50 healthy adult (30-mo-old) primiparous G?ttingen minipigs, we studied the short-term (8 mo, n = 30) and long-term (15 mo, n = 10) effect of GC on bone and mineral metabolism longitudinally and cross-sectionally compared with a control group (n = 10). All animals on GC treatment received prednisolone orally at a dose of 1.0 mg x kg body wt(-1) x day(-1) for 8 wk and thereafter at 0.5 mg/kg body wt(-1) x day(-1). In the short term, GC reduced bone mineral density (BMD) at the lumbar spine by -47.5 +/- 5.1 mg/cm(3) from baseline (P < 0.001), which was greater (P < 0.05) than the loss [not significant (NS)] in the control group of -11.8 +/- 12.6 mg/cm(3). Calcium absorption decreased from baseline by -2,488 +/- 688 mg/7 days (P < 0.001) compared with -1,380 +/- 1,297 mg/7 days (NS) in the control group. Plasma bone alkaline phosphatase (BAP) decreased from baseline by -17.8 +/- 2.2 U/l (P < 0.000), which was significantly different (P < 0.05) from the value of the control group of -1.43 +/- 4.8 U/l. In the long term, the loss of BMD became more pronounced and bone mineral content (BMC), trabecular thickness, mechanical stability, calcium absorption, 25-hydroxyvitamin D(3), 1,25-dihydroxyvitamin D(3), and parathyroid hormone tended to be lower compared with the control group. There was a negative association between the cumulative dose of GC and BMD, which was associated with impaired osteoblastogenesis. In conclusion, the main outcomes after GC treatment are comparable to symptoms of GC-induced osteoporosis in human subjects. Thus the adult G?ttingen miniature pig appears to be a valuable animal model for GC-induced osteoporosis.     

Effects of physical training on bone mineral density and bone metabolism

The purpose of this study was to examine the influences of long-term walking training and walking and jumping training on bone mineral density (BMD) and bone metabolism. Data from 28 healthy premenopausal women was assessed. The subjects were divided into the walking group (WG; 17 women mean+/-SE age 35+/-2 years), and the walking and jumping group (WJG; 11 women mean+/-SE age 39+/-1 years). BMD was measured in the lumbar spine and proximal femur using dual energy X-ray absorptiometry (DXA). As markers of bone metabolism, this study was to measure bone formation markers, bone-alkaline phosphatase (B-ALP: measured by enzyme immunoassay/EIA) and osteocalcin (BGP: by radioimmunoassay/RI) as well as bone resorption markers, parathyroid hormone (PTH: measured by/RI) and type I collagen cross-linked N-telopeptides (NTx: by EIA). Despite the significant decrease in body weight (p<0.05), no corresponding decrease in BMD was observed. Moreover, no significant difference in bone markers BGP, PTH, and NTx was observed. B-ALP was significantly increased (p<0.05) after one year, and the rate of this increase was greater in the WJG than in the WG. It is thus concluded that walking training for one year is beneficial for the promotion of bone formation, and that jumping stimulus maintain BMD effectively.     

Influence of cardiovascular disease risk factors on the relationship between low bone mineral density and type 2 diabetes mellitus in a multiethnic us population of women and men: A cross-sectional study

Introduction: Higher bone mineral density (BMD) has been reported among white women and men with type 2 diabetes mellitus (DM) compared with nondiabetic white individuals, but there is scant evidence for nonwhite persons. It is also not known whether cardiovascular disease (CVD) risk factors may confound any association between BMD and type 2 DM.Objective: The present study examined the relationship between low BMD and type 2 DM in a multiethnic population of women and men while controlling for the influence of osteoporosis and CVD risk factors including body mass index (BMI), cigarette smoking, physical inactivity, total cholesterol and its components, blood pressure, and C-reactive protein.Methods: Data collected from 4929 African American, Mexican American, and white women and men aged 50 to 79 years who participated in the household interview and clinical examinations during the Third National Health and Nutrition Examination Survey were analyzed. CVD risk factors associated with type 2 DM in this study population were included as covariates in gender-specific multiple logistic regression models assessing the relationship between type 2 DM and low BMD while controlling for osteoporosis risk factors. Gender- and race/ethnicity-specific mean BMD values at the total hip for young adults aged 20 to 29 years were used to establish race/ethnicity and gender-specific low BMD T-scores.Results: The final study population included 2505 women and 2424 men. More women and men with type 2 DM than women and men without type 2 DM were nonwhite and had high BMI. Osteoporosis risk factors but not CVD risk factors were associated with low BMD in both women and men. Type 2 DM was not associated with low BMD among women (odds ratio [OR] = 0.77; 95% CI, 0.56-1.08). Based on a statistically significant interaction between type 2 DM status and race/ethnicity, white men with type 2 DM were less likely to have low BMD than were white men without type 2 DM (OR = 0.56; 95% CI, 0.37-0.86; P = 0.01). There was no significant BMD difference between diabetic and nondiabetic nonwhite men.Conclusion: CVD risk factors did not appear to influence the relationship between low BMD and type 2 DM in this study