Bone Metabolism In Elderly Women Research Articles

Effects of a 20-Week Concurrent Training Program on Bone Metabolism in Elderly Women

Effects of a 20-Week Concurrent Training Program on Bone Metabolism in Elderly Women

Impaired gamma carboxylation of osteocalcin in elderly women with type II diabetes mellitus: relationship between increase in undercarboxylated osteocalcin levels and low bone mineral density.

We conducted a cross-sectional examination of the role of serum vitamin K levels as they relate to bone metabolism in elderly women with type II diabetes mellitus (DM). Eighty-five elderly women with type II DM were enrolled. Three fractions of vitamin K, phylloquinone (PK), menaquinone 4 (menatetrenone; MK 4), and menaquinone 7 (MK 7), along with undercarboxylated osteocalcin (UcOC), intact osteocalcin (IOC), urinary deoxypyridinoline (udpd), urinary type I collagen N-telopeptide (NTx), and intact parathyroid hormone (IPTH) were measured. Bone mineral density was measured in the lumbar spine (LSBMD) by dual-energy X-ray absorptiometry (DXA), and T scores or Z scores were calculated. The patients were divided into two groups by T score, under -2.5 (osteoporotic group) and over -2.5 (non-osteoporotic group). UcOC levels in osteoporotics patients were significantly higher than those in the non-osteoporotic group (3.09 +/- 3.94 vs 1.82 +/- 1.76 ng/ml, P = 0.02). The correlation between Z score and logarithmic UcOC/IOC levels in type II DM showed a negative trend ( P = 0.07) and a significantly and negatively association with logarithmic NTx ( r = -0.38; P = 0.001). In osteoporotic DM, the UcOC/IOC ratio was significantly correlated with the Z score ( r = -0.61; P << 0.05). Furthermore, logarithmic UcOC/IOC showed a negative correlation with logarithmic MK 7 ( r = -0.50; P = 0.001). In conclusion, the reduction in LSBMD in elderly women with type II DM may be associated, in part, with a defect in Gamma-glutamylcarboxylation by vitamin K.

Calcium-sensing receptor gene polymorphism A986S does not predict serum calcium level, bone mineral density, calcaneal ultrasound indices, or fracture rate in a large cohort of elderly women.

Postmenopausal osteoporosis is a complex and heterogeneous disease influenced by multiple factors and related to peak bone mass achieved in early adult life, followed by a subsequent continuous bone loss. Genetic variance and polymorphisms have been shown to be of clinical significance for osteoporotic fragility fractures. Previous studies have related variations in the calcium sensor receptor (CASR) gene to circulating Ca levels and bone mass in young women and adolescent girls. The aim of this study was to investigate the impact of the A986S polymorphism of the CASR gene on calcium homeostasis and bone metabolism in elderly women. We studied the distribution of the A986S polymorphism in a large cohort of 1252 ambulatory Australian women in relation to biochemical markers of bone metabolism, bone mass evaluated by quantitative ultrasound measurements (QUS) and DXA of the hip, prevalent and 36-month incident fracture data. No effect of the polymorphism was found on circulating calcium level, renal Ca excretion, or biochemical markers of bone turnover. Moreover, A986S was not associated with bone mass or prevalent or incident fractures. Power calculations revealed that a difference in circulating calcium levels of 0.05 mmol/l, a difference in DXA bone density of 24 mg, and a 1.6-fold difference in fracture rate could have been detected with a power of 80%. In conclusion, in a large cohort of elderly women the A986S polymorphism of the CASR gene was not found to be significant for calcium homeostasis or bone mass. It is questioned whether the polymorphism has any clinical significance for postmenopausal osteoporosis.

Alcohol intake and bone metabolism in elderly women

Published reports on the effect of alcohol consumption on bone mineral density (BMD) are inconsistent. The objective of this study was to examine the relation between alcohol intake and BMD, calcitropic hormones, calcium absorption, and other biochemical indexes of bone and mineral metabolism in elderly women. The results presented are derived from baseline observations of 489 elderly women (aged 65-77 y) recruited for an osteoporosis study. The nondrinking group comprised 297 women and the drinking group comprised 148 women. Furthermore, the effect of different alcohol intakes (</=28.6, >28.6 to </=57.2, >57.2 to </=142.9, and >142.9 g/wk) was studied. Women who consumed alcohol had significantly higher spine (10%), total body (4.5%), and midradius (6%) BMD than did nondrinkers. An alcohol intake >28.6 g/wk was associated with higher BMD; maximum effect was seen with an intake of >28.6 to </=57.2 g/wk (16%, 12%, and 14% increase in spine, total body, and midradius BMD, respectively). There was a marked reduction in bone remodeling markers, serum osteocalcin, and the ratio of urinary cross-linked N:-telopeptides of type 1 collagen to creatinine with alcohol consumption, suggesting that increased BMD with alcohol consumption could be due to reduced bone remodeling. Further, serum parathyroid hormone concentrations were significantly lower in alcohol drinkers than in nondrinkers and could be one of the causes of decreased bone resorption. Moderate alcohol intake was associated with higher BMD in postmenopausal elderly women. The protective effect of alcohol may have been a result of lower bone remodeling due to reduced parathyroid hormone concentrations or factors such as increased estrogen concentrations.

Smoking and bone metabolism in elderly women

Cigarette smoking has been implicated as a risk factor for osteoporosis. In the present study, the relationship between smoking and bone mineral density, calcitropic hormones, calcium absorption, and biochemical indices related to bone and mineral metabolism was examined at baseline, in subjects recruited for an osteoporotic study. The subjects included 489 elderly women, aged 65–77 years. After exclusions (thiazide users), 54 women constituted the smoking group and 390 women were classified as nonsmokers. The effect of frequency of smoking was also examined in this population (33 light smokers [<1 pack/day] and 21 heavy smokers [>1 pack/day]). Adjusted mean total body bone mineral density was 4% lower (0.968 ± 0.019 vs. 1.009 ± 0.004) and the total hip density was 6% lower (0.778 ± 0.024 vs. 0.826 ± 0.006) in heavy smokers compared with nonsmokers. At the other sites measured (spine, midradius, femoral neck, trochanter, and Ward’s triangle), a similar nonsignificant trend was observed. The adjusted mean calcium absorption corrected for weight was lower (13%) both in light and heavy smokers compared with nonsmokers, and serum 25-hydroxyvitamin D was significantly lower (16%) in heavy smokers than nonsmokers. Serum parathryroid hormone (PTH) was higher in heavy smokers, but was not significantly different from that of nonsmokers. A significant increase in bone remodeling markers, serum osteocalcin (4.35 ± 0.271 vs. 3.79 ± 0.066) and urine N-telopeptide/creatinine (NTx/Cr) ratio (74.5 ± 5.75 vs. 49.8 ± 1.4) was seen in heavy smokers compared with nonsmokers. These results suggest that smoking lowers bone mineral density, and is a result of decreased calcium absorption associated with secondary hyperparathyroidism and increased bone resorption.