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Biomedical subjects

P Lips

Publications and source records attributed to P Lips.

At least 109 records · Page 6Linked to original sources
PubMed1996

Different risk profiles for hip fractures and distal forearm fractures: a prospective study.

In a prospective cohort of elderly persons, aged 70 years and over, we examined risk indicators for which data could be easily obtained, to construct risk profiles for hip fractures and distal forearm fractures. Participants lived independently, in apartment houses for the elderly or in homes for the elderly. At baseline, information was obtained in 2578 subjects on age, gender, residence, mobility and the frequency of going outdoors. Mobility was measured using a walking score ranging from 1 (not able to walk independently) to 3 (able to walk independently for a fair distance). During the study period (median duration 3.5 years, maximum 4 years) 106 participants sustained a hip fracture and 60 participants suffered a distal forearm fracture. Women compared with men, adjusted for age, had a higher risk of hip fracture (adjusted relative risk (RR) = 2.4, 95% confidence interval (CI) 1.3-4.3) and distal forearm fracture (RR = 3.7, 95% CI 1.5-9.2). Age, adjusted for gender, was related to hip fractures only: the relative risk of fracture for those in the highest age category (> 85 years) was 9.5 (95% CI 4.3-21.2) compared with those in the lowest age category (70-75 years). Moderately impaired walking ability compared with normal walking ability, adjusted for age and gender, was associated with a higher risk of hip fracture (RR = 1.8, 95% CI 1.2-2.7) but with a lower risk of distal forearm fracture (RR = 0.4, 95% CI 0.2-0.8). The outdoor score, adjusted for age and gender, was associated with distal forearm fractures only: going outdoors less than once a week, compared with three times or more, was associated with a lower risk of fractures (RR = 0.3, 95% CI 0.1-0.9). In those living in homes for the elderly the risk of hip fracture was higher compared with those living independently (RR = 2.4, 95% CI 1.4-4.2), adjusted for age and gender. Risk profiles were constructed using stepwise Cox's proportional-hazards regression. The risk profile predicted probabilities of sustaining a hip fracture in a 4-year period ranging from 0.4% to 25.9%, and of distal forearm fractures ranging from 0.2% to 4.5%, depending on the subject's characteristics as defined by the risk indicators. We conclude that easily obtainable risk indicators can be used in the prediction of fractures and can discriminate among fracture types.

Accidental Falls↗
PubMed1996

Osteocyte density changes in aging and osteoporosis.

Recently, it was suggested that osteocytes are involved in the regulation of bone remodeling. We have examined human trabecular bone of the iliac crest of fracture patients and control subjects to determine if osteoporosis is associated with changes in osteocyte density or osteocyte death. The relationships of these parameters with age was also investigated. It was found that osteocyte death was not related to age, nor was it increased in osteoporosis compared with the controls. In healthy adults ranging from 30 to 91 years, lacunar number per bone area decreases with advancing age, from about 210/mm(2) to 150/mm(2). Significantly higher lacunar and osteocyte numbers per bone tissue volume were found in osteoporotics than in controls (17,100 lacunae/mm(3) and 13,300 osteocytes/mm(3) vs. 12,900 lacunae/mm(3) and 10,500 osteocytes/mm(3), respectively), whereas lacunar area was significantly reduced in osteoporotics (from 44.1 mu m(3) to 39.1 mu m(2)). These findings are compatible with the hypothesis that, in osteoporosis, osteoblasts produce less bone per cell. This can in turn explain the reduced wall thickness, which has previously been described as characteristic for osteoporosis.

Adult↗
PubMed1996

Prevention of hip fractures: drug therapy.

Drug therapy to prevent hip fractures may be considered for postmenopausal women with low bone mass and elderly people with risk factors for hip fracture. As most hip fractures occur 25 years or more after menopause, drug therapy may have to be prescribed for many years to be effective. A preventative drug should be effective, safe, and without side effects. Estrogen therapy decreases bone loss and hip fracture incident, but the effect wears off when treatment is stopped. The positive effect of estrogens on cardiovascular disease should be balanced against the increased risk of breast cancer with long-term use. The newer bisphosphonates are potent inhibitors of bone resorption and decrease bone loss substantially. Again, the effect may wear off after the drug is stopped. The bisphosphonates appear to be safe, but long-term data are lacking. Calcium and/or vitamin D may prevent bone loss in late postmenopausal women and elderly people. The combination was shown to prevent hip fractures and other peripheral fractures in elderly nursing home residents. No single drug will be used more than 10-15 years. Therefore, a public health strategy should be developed with a logical sequence of drug and nondrug interventions for the successful prevention of hip fractures.

Aged↗
PubMed1996

Histomorphometric analysis of bone mass and bone metabolism in growth hormone deficient adult men.

Transiliac bone biopsies were obtained from 36 growth hormone (GH) deficient men (mean age +/- SD, 28 +/- 4 years), of which 13 had an isolated GH deficiency and 23 had partial or complete hypopituitarism. The latter group was adequately substituted for the pituitary hormone deficiencies other than GH. Static histomorphometry was compared with eight controls, and dynamic histomorphometry was compared with six healthy men matched for age. Mean trabecular bone volume was not decreased and bone volume was high (> 30%) in ten patients. Osteoid thickness and mineralization lag time were slightly although not significantly higher than in controls. Osteoid surface, mineralizing surface and bone formation rate tended to be lower than in the controls. The eroded surface was significantly higher (p < 0.002) in the GH deficient patients. The results demonstrate that GH deficient patients do not show trabecular osteoporosis. The increased eroded surface together with normal to increased bone volume and bone surface suggests a prolonged reversal phase or a less sufficient coupling phenomenon.

Adult↗
PubMed1996

Ultrasound measurements in the calcaneus: precision and its relation with bone mineral density of the heel, hip, and lumbar spine.

Broadband ultrasound attenuation (BUA) and speed of sound (SOS) in the heel are suggested to measure bone density and structure and to predict fracture risk. Short-term precision (five consecutive measurements in 1 h) and long-term precision (six within 3 months) of ultrasound parameters were studied in 20 healthy subjects. The coefficient of variation (CV) did not change over a 3-month period for SOS (1.3%). Short-term precision of BUA was 3.4% (CV) and long-term precision was 4.9% (CV) (not significantly different: p = 0.09). Relationships between ultrasound parameters and BMD at various sites were examined in 42 subjects. BMD at the heel was assessed at the location corresponding to that of the ultrasound measurements (BMDheel). Correlation coefficients, corrected for imprecision in the measurements, for BUA and SOS vs. BMDheel, were 0.81 and 0.76, respectively. The correlation coefficients between heel measurements (BUA, SOS, and BMDheel) and BMD in the hip and lumbar spine ranged from 0.37 to 0.57. The relationships between BUA, SOS, and BMDheel vs. BMD of the hip were modified by physical activity and body weight. Higher physical activity and body weight were associated with higher BMD values at the hip. BUA values < 60 dB/MHz predicted BMD at the femoral neck < 0.70 g/cm2 with a sensitivity and specificity of 80% and 93%, respectively. After the age of 30, 11 participants had sustained vertebral fractures and 12 participants nonvertebral osteoporotic fractures. BUA and SOS values were significantly lower in fracture patients than in participants without fractures. It can be concluded that ultrasound measurements at the heel correlate well to BMD at the same site. BUA can predict BMD at the hip and is lower when the subject has sustained fractures.

Adult↗
PubMed1996

The effect of one-year cross-sex hormonal treatment on bone metabolism and serum insulin-like growth factor-1 in transsexuals.

The effects of treatment with estrogens and antiandrogens in male to female (M-->F) transsexuals and androgens in female to male (F-->M) transsexuals on their respective bone metabolism, bone mineral density (BMD), serum insulin-like growth factor I (IGF-I) and IGF-binding protein-3 (IGFBP-3) levels were investigated. BMD and variables of bone turnover in serum were measured at baseline and after 3 months (except for BMD) and 1 yr of treatment in 56 M-->F and 35 F-->M transsexuals. Serum IGF-I, IGFBP-3, and propeptide of type I procollagen (P1CP) were measured at baseline and after 1 yr of treatment in 10 M-->F and 10 F-->M transsexuals. In M-->F, BMD increased significantly. Bone turnover decreased, as shown by a significant decline in levels of osteocalcin, alkaline phosphatase, P1CP, and fasting urinary calcium/creatinine and hydroxyproline/creatinine ratios. Serum IGF-I levels decreased significantly without significant changes in IGFBP-3 levels. In F-->M, BMD did not change. Bone formation increased, as suggested by an increase in alkaline phosphatase and a borderline increase in P1CP values. IGF-I levels increased significantly, whereas no significant changes were seen in IGFBP-3 levels. We conclude that in males, estrogens (in combination with antiandrogens) decrease bone turnover, with a subsequent increase in BMD and a decrease in serum IGF-I. In females, testosterone administration increases bone formation, but this is not reflected in an increased BMD, whereas serum IGF-I increases.

Adolescent↗
PubMed1996

The development of a European questionnaire for quality of life in patients with vertebral osteoporosis.

The complaints of vertebral osteoporosis usually result from wedge or crush fractures and biconcave deformities. These are caused by a decrease of bone mass and deterioration of bone structure leading to loss of strength. Treatment of osteoporosis should result in an increase of bone mass, and the incidence of new vertebral fractures should diminish. However, new vertebral fractures are not always accompanied by pain, and disability does not well correlate with the number of vertebral fractures. Patients with osteoporosis often have other problems e.g. with taking a shower, preparing meals, gardening, walking stairs, visiting friends and attending social activities. In addition, pain and disability may influence mood and lead to depression. The assessment of quality of life should be a primary endpoint in clinical trials in patients with osteoporosis and in individual patients care. Recently, the European Foundation for Osteoporosis (EFFO) has decided a develop a questionnaire for patients with vertebral osteoporosis, i.e. patients with vertebral deformities. The questionnaire is meant for use in clinical trials. A questionnaire was made including 48 questions and 6 visual analogue scales. The questions concern the following domains: pain, activities of daily living, jobs around the house, moving, leisure and social activities, general health perception and mood. The questionnaire ("Qualeffo") has now entered the validation phase. The first study in 8 centres concerns the within-subject reproducibility, the internal coherence, and the specificity by comparing osteoporotic patients with a control group not suffering from osteoporosis or backpain.

Humans↗
PubMed1995

Vitamin D status and sex hormone binding globulin: determinants of bone turnover and bone mineral density in elderly women.

To examine the relation of the vitamin D status and the remaining estrogen activity with bone turnover and bone mineral density (BMD) in elderly women, BMD was measured at both hips using dual-energy X-ray absorptiometry and at the distal radius using single photon absorptiometry, in 330 healthy women aged 70 and over. Vitamin D metabolites, sex hormone binding globulin (SHBG), PTH(1-84), osteocalcin, alkaline phosphatase, and hydroxyproline and calcium excretion in 2 h fasting urine were measured. Multiple linear regression was used to adjust for potential confounders. In 65% of the women, serum 25(OH)D was below 30 nmol/l. Only values below a threshold for 25(OH)D were negatively related to serum PTH(1-84) (p = 0.02, threshold at 25 nmol/l) and to osteocalcin levels (p = 0.04, threshold at 30 nmol/l). BMD of the femoral neck and trochanter was positively related to serum 25(OH)D (left neck p = 0.001) with thresholds at 30 nmol/l whereas the distal radius was not (p = 0.32). Serum PTH was negatively related to BMD at all measurement sites (all p < 0.001). Serum SHBG, an inverse measure of estrogen activity, was positively related to osteocalcin levels (p = 0.004) and the urinary hydroxyproline/creatinine ratio (p = 0.002) and negatively related to the BMD of the trochanter (left trochanter p = 0.02) and the distal radius (p = 0.001). We conclude that in elderly women, serum 25(OH)D levels below 30 nmol/l are associated with secondary hyperparathyroidism and increased bone turnover. SHBG is positively related to bone turnover.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1995

Prevention of bone loss by vitamin D supplementation in elderly women: a randomized double-blind trial.

The purpose of the study was to determine the effect of vitamin D supplementation on bone turnover and bone loss in elderly women. Three hundred forty-eight women, ages 70 yr and older, were randomized to receive 400 IU vitamin D3 per day (n = 177) or placebo (n = 171), double-blind, for a period of 2 yr. Main outcome measures were bone mineral density of both hips (femoral neck and trochanter) and the distal radius, as well as biochemical markers of bone turnover. The effect of vitamin D supplementation was expressed as the difference in mean (percentage) change between the placebo group and the vitamin D group. The measurements were repeated in 283 women after 1 yr and in 248 women after 2 yr. Vitamin D supplementation significantly increased serum 25-hydroxyvitamin D (250HD) (+35 nmol/L) and 1,25-dehydroxyvitamin D [1,25-(OH)2D] (+7.0 pmol/L) levels and urinary calcium/creatinine ratios (+0.5%) and significantly decreased PTH(1-84) secretion (-0.74 pmol/L) after 1 yr. No effect was found for the parameters of bone turnover. The effect on the bone mineral density of the left femoral neck was +1.8% in the first yr, +0.2% in the second yr, and +1.9% during the whole period (95% confidence interval 0.4, 3.4%). At the right femoral neck the effects were +1.5%, +1.1%, and +2.6% (confidence interval 1.1, 4.0%), respectively. No effect was found at the femoral trochanter and the distal radius. Supplementation with 400 IU vitamin D3 daily in elderly women slightly decreases PTH secretion and increases bone mineral density at the femoral neck.

Aged↗
PubMed1995

Additional weight-bearing during exercise is more important than duration of exercise for anabolic stimulus of bone: a study of running exercise in female rats.

Mechanical loading is necessary for maintenance of skeletal integrity, but the most effective type, intensity, and duration of exercise are not known. In vivo experiments have indicated that the strain generated by the stimulus is more important than the duration of the stimulus. To elucidate this question, we studied 5-month-old female Wistar rats exercised on a motor-driven exercise belt for 17 weeks, 5 days per week (average velocity 20 m/min). Group 1 served as controls, group 2 was trained for 30 min, group 3 was trained for 30 min with a 50-g backpack, and group 4 was trained for 15 min with a 50-g backpack. Total body bone mineral content (BMC), bone mass of the lower extremities (LEBMC), total body lean soft-tissue mass (LSTM), and total body fat-tissue mass (FTM) were measured by dual-energy absorptiometry (DXA) at 0, 6, and 17 weeks. The BMC increased more in group 4 than in controls (15% vs. 8%, p < 0.03). In the other two intervention groups, no significant increases of total body BMC occurred compared with controls, although a trend was observed (12%). The LEBMC increased significantly in all exercising groups after 17 weeks, being 16% in group 2, 15% in group 3, and 20% in group 4, compared with 6% in controls (p < 0.05). The increase in LSTM after 6 weeks was most pronounced in group 3, at 20%, compared with 10% in the control group (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1995

Two bone alkaline phosphatase assays compared with osteocalcin as a marker of bone formation in healthy elderly women.

Serum bone alkaline phosphatase (ALP; EC 3.1.3.1) was measured with a wheat germ agglutinin (WGA) precipitation assay and with a new IRMA in a group of healthy elderly women. Both assays were correlated with serum total ALP activity and with osteocalcin. The two bone ALP assays have comparable within- and between-run imprecisions (WGA assay within-run CVs 2.6-5.4% and between-run, 4.0-5.1%; IRMA within-run CV 5.0% and between-run, 3.2%). Comparison of the WGA precipitation assay (x) with the IRMA (y) demonstrated a correlation coefficient of 0.87 [Deming regression equation: y = (0.58 +/- 0.02)x - (4.62 +/- 0.45); n = 101; Sy/x = 1.26; P < 0.001). Correlation studies with osteocalcin and total ALP showed correlation coefficients (all P < 0.001) of 0.34 and 0.65, respectively, for the WGA precipitation assay and of 0.36 and 0.68, respectively, for the IRMA. We conclude that the two bone ALP assays have similar imprecision and that neither can be given preference over the other as a marker of bone turnover.

Aged↗
PubMed1994

Long-term effect of calcium supplementation on bone loss in perimenopausal women.

We observed in a controlled 2 year longitudinal trial in 248 perimenopausal women that a daily calcium supplement of either 1000 or 2000 mg Ca2+ significantly reduced lumbar bone loss and bone turnover in the first year of calcium supplementation. In the second supplementation year the rate of lumbar bone loss in the treated subjects was not significantly different from that in the control group, although two of the three biochemical parameters of bone turnover remained decreased throughout the study. To quantify further the long-term effect of calcium supplementation, we extended the study for another year in 214 women. In the women of the control group who were menstruating until the last year of the trial, the mean change in lumbar bone mineral density after 3 years was -3.2% of the initial value versus 1.6% in the calcium-supplemented groups (p < 0.01). The decrease in lumbar bone loss in these supplemented premenopausal and early perimenopausal women remained statistically significant in the second and third years of supplementation. In the women who stopped menstruating before or during the study, the long-term reduction in lumbar bone loss was not significant (mean difference between control and treatment groups < 0.6% points after 3 years). The decrease in metacarpal cortical thickness (MCT) in the treated subjects during 3 years was on average -3.0% of the initial value in the control versus -2.0% in the supplemented subjects (P < 0.01). The effect of calcium supplementation on MCT was not significantly related to the menopausal status of the subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1994

Weight-bearing activity during youth is a more important factor for peak bone mass than calcium intake.

In a 15 year longitudinal study (Amsterdam Growth and Health Study) is evaluated the effect of daily calcium intake (CAI) during adolescence and young adulthood on the development of peak bone mass at age 27 when the influence of weight-bearing activity (WBA) and body weight was accounted for. A group of 84 males and 98 females were measured longitudinally from age 13 until age 28. Measurements were taken six times of anthropometric characteristics. Lifestyle was also evaluated six times by cross-check interviews of CAI and WBA. Bone mineral density (BMD) of the lumbar spine was determined at age 27 by dual x-ray absorption. Three periods were considered, that is, the adolescent period, the period 13-21 years, and the total period (13-27 years). In multiple linear regression analyses, only WBA and body weight were significant positive contributors to the final model of lumbar BMD at age 27. In all three periods WBA was the best predictor in males and body weight in females. ANOVA was performed on BMD and the highest and lowest quartiles of calcium intake with the significant predictor variables of the linear regression model as covariates. Again calcium intake appeared not a significant predictor of BMD in the three periods in both sexes. Regular weight-bearing exercise and at least a normal age-related body weight in adolescence and young adulthood are of key importance in reaching the highest lumbar peak bone mass at the age of 27 years.

Absorptiometry, Photon↗
PubMed1994

Consequences of childhood-onset growth hormone deficiency for adult bone mass.

To assess the implications of prolonged growth hormone deficiency (GHD) for the acquisition and maintenance of bone mass, bone mineral density (BMD) was measured in 70 adult males (mean age 26.7 +/- 4.5 years) with childhood-onset GHD, 7.4 +/- 4.2 years after discontinuation of previous GH therapy. Because most of these patients were short (mean height 165.8 +/- 6.6 cm), the influence of body height on standard BMD measurements, conventionally reported as the areal density (BMDarea, expressed in g/cm2), was analyzed in a group of age-matched healthy males. In GHD patients, BMDarea was significantly reduced at the lumbar spine (Z score -1.59 +/- 1.08, p < 0.001) as well as at the nondominant hip (Z score -1.18 +/- 0.95, p < 0.001). The reduction in BMDarea was similar for patients with isolated GHD (N = 25) and those with combined deficiencies of GH and luteinizing hormone (N = 40). In patients and controls, BMDarea was positively correlated with body height, a relation that was attributed to skeletal size. Bone dimensions were significantly smaller in patients than in controls, and therefore it was hypothesized that the difference in areal density between patients and controls might be confounded by differences in bone size. Measured bone mineral content corrected for the estimated bone volume (BMDvolume, expressed in g/cm3) remained significantly reduced (Z score: lumbar spine, -0.90 +/- 1.08, p < 0.001; femoral neck, -0.74 +/- 1.00, p < 0.001), but the differences between GHD patients and controls were less than indicated by BMDarea (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

The incidence of hip fractures in independent and institutionalized elderly people.

The incidence density of hip fractures in the population of Amsterdam, aged 70 years and over, was studied according to the type of residence. In 1989, 655 patients were admitted to nine hospitals within Amsterdam for a hip fracture. Postal codes were used to classify the residence of the population and the hip fracture cases as independent, home for the elderly or nursing home. Stepwise logistic regression was used for data analysis. The risk of hip fracture increased with age and was 1.7 times higher for women than for men. In the age group 70-74 years the relative risk (RR) was 7.6 for those in homes for the elderly and 5.8 for those in nursing homes, when compared with the independent elderly. This RR was approximately 1 for those in homes for the elderly aged 85 years and over. However, in nursing homes the RR was still 2.8 in the age group 95+. We concluded that, despite protective measures against falls, the institutionalized elderly are at greater risk of hip fracture than the independent elderly of the same age and sex. This higher risk is especially apparent in the 'younger' age groups.

Age Factors↗