Prevalence and seasonal variation of hypovitaminosis D and its relationship to bone metabolism in healthy Hungarian men over 50 years of age: the HunMen Study

Summary

This study reports a high prevalence of hypovitaminosis D and low bone mineral density (BMD) in a healthy Hungarian male cohort over 50 years of age. Men with 25-hydroxyvitamin D levels of <75 nmol/L had a significantly higher 10-year hip and major osteoporotic fracture probability using the country-specific fracture risk assessment (FRAX) algorithm.

Introduction

The aim of this study is to characterize the prevalence and seasonal variation of hypovitaminosis D and its relationship to bone metabolism in healthy Hungarian men over 50 years of age.

Methods

We determined levels of 25-hydroxyvitamin D (25-OH-D), PTH, osteocalcin (OC), C-terminal telopeptides of type-I collagen (CTX-I), procollagen type 1 amino-terminal propeptide (PINP), BMD at L1–L4 (LS) and femur neck (FN), daily dietary calcium intake, and the 10-year probability of hip fracture and a major osteoporotic fracture using the country-specific FRAX algorithm in 206 randomly selected ambulatory men.

Results

The mean (range) age of the volunteers was 60 (51–81) years. The prevalence of hypovitaminosis D (25-OH-D, <75 nmol/L) was 52.9%. The prevalence of low (T-score?<??1.0) BMD at the FN and LS was 45% and 35.4%, respectively. The mean (range) FRAX hip fracture and FRAX major osteoporotic fracture was 0.8% (0–9.4%) and 3.8% (1.7–16%), respectively. On comparing the vitamin D sufficient to the insufficient group, there was a statistically significant difference between the FRAX hip fracture and FRAX major osteoporotic fracture indexes. There was significant seasonal variation in the vitamin D levels; the lowest levels were measured in winter and the highest in summer.

Conclusions

A high prevalence of hypovitaminosis D and low BMD were observed in the studied Hungarian male population. This is the first study reporting higher 10-year hip and major osteoporotic fracture probability using the country-specific FRAX algorithm in individuals with hypovitaminosis D.     

Calcium absorption and bone mineral density in celiacs after long term treatment with gluten-free diet and adequate calcium intake

Calcium malabsorption, hypocalcemia and skeletal demineralization are well-recognized features of untreated celiac disease. This study investigates calcium absorption and bone mineral density (BMD) after a prolonged, over 4 years, treatment with a gluten-free diet. Twenty-four adult females with treated celiac disease and twenty age- and sex-matched control subjects were studied. Mean body mass index (MBI), energy intake, serum calcium, and serum 25(OH)D concentrations in treated celiacs did not differ from controls. However, while both dietary calcium and protein intake were significantly higher in celiacs (P<0.012), fractional calcium absorption was lower (mean percentage±SD; treated 39.8±12 versus controls 52.3±10, P<0.001). Thus, after adjusting for calcium intake, the estimated amount of calcium absorbed daily was similar in both groups. Whole body, spine and trochanter BMD were significantly lower in treated celiac patients compared with controls (P<0.05). There were significant inverse correlations between: serum parathyroid hormone (PTH) and femoral neck or total body BMD (P<0.01), PTH and duration of gluten-free diet (P=0.05), and fractional calcium absorption and alkaline phosphatase (P=0.022). Increased calcium intake could potentially compensate for the reduced fractional calcium absorption in treated adult celiac patients, but may not normalize the BMD. In addition, the inverse correlation between PTH and time following treatment is suggestive of a continuing long-term benefit of gluten withdrawal on bone metabolism in celiac patients.     

Preferential low bone mineral density of the femoral neck in patients with a recent fracture of the proximal femur

Bone mass is an important determinant of resistance to fractures. Whether bone mineral density (BMD) in subjects with a fracture of the proximal femur (hip fracture) is different from that of age-matched controls is still debated. We measured BMD of the femoral neck (FN) on the opposite side to the fracture, as well as femoral shaft (FS) and lumbar spine (LS) BMD by dual-photon absorptiometry in 68 patients (57 women and 11 men, mean age 78.8±1.0) 12.4±0.8 days after hip fracture following a moderate trauma. These values were compared with BMD of 93 non-fractured elderly control subjects (82 women and 11 men), measured during the same period. As compared with the controls, FN BMD was significantly lower in fractured women (0.592±0.013 v. 0.728±0.014 g/cm²,P<0.001) and in fractured men (0.697±0.029 v. 0.840±0.052,P<0.05). Expressed as standard deviations above or below the mean BMD of age and sex-matched normal subjects (Z-score), the difference in FN BMD between fractured women and controls was highly significant (–0.6±0.1 v. +0.1±0.1,P<0.001). As compared with mean BMD of young normal subjects, BMD was decreased by 36.9±1.4 and 22.4±1.5% (P<0.001) in fractured and control women, respectively. There was no significant difference between FN BMD of 33 women with cervical and 24 with trochanteric hip fractures (0.603±0.017 v. 0.577±0.020). FN BMD was lower than 0.705 g/cm² in 90% of fractured women. The prevalence of fracture increased with decreasing FN BMD, reaching 100% with values below 0.500 g/cm². FS and LS BMD were significantly lower in women with hip fracture than in controls (1.388±0.036 v. 1.580±0.030,P<0.001, for FS, and 0.886±0.027 v. 0.985±0.023,P<0.01, for LS), but these differences were not significant when expressed as a Z-score. In men with a recent hip fracture, FS BMD was significantly lower than in controls (1.729±0.096 v. 2.069±0.062,P<0.01), but the difference at the LS level did not reach statistical significance. These results indicate that both women and men with a recent hip fracture had decreased bone mineral density of the femoral neck, femoral shaft and lumbar spine. However, the difference appeared to be of higher magnitude for the femoral neck suggesting a preferential bone loss at this site.     

Relation between vitamin D insufficiency, bone density, and bone metabolism in healthy postmenopausal women.

Although only few postmenopausal women exhibit biochemical signs of hypovitaminosis D, vitamin D insufficiency has been shown to have adverse effects on bone metabolism and could be an important risk factor for osteoporosis and fracture. We determined serum levels of 25-hydroxyvitamin D [25(OH)D], intact parathyroid hormone (iPTH), bone turnover markers, dietary calcium intake, and bone mineral density (BMD; measured by dual X-ray absorptiometry) in 161 consecutive ambulatory women, healthy except for osteoporosis, referred to a bone metabolic unit. The prevalence of vitamin D insufficiency [25(OH)D < or = 15 ng/ml] was 39.1%. 25(OH)D was lower in the osteoporotic subjects (15.7 +/- 5.3 ng/ml vs. 21.8 +/- 9.7 ng/ml; p < 0.001). After controlling for all other variables, lumbar spine (LS) BMD was found to be significantly associated with 25(OH)D, body mass index (BMI), and years after menopause (YSM) (R2 = 0.253; p < 0.001). For femoral neck (FN), significant independent predictors of BMD were YSM, BMI, iPTH, and 25(OH)D (R2 = 0.368; p < 0.001). The probability of meeting osteoporosis densitometric criteria was higher in the vitamin D insufficiency group (odds ratio [OR], 4.17, 1.83-9.48) after adjusting by YSM, BMI, iPTH, and dietary calcium intake. Our study shows that vitamin D insufficiency in an otherwise healthy postmenopausal population is a common risk factor for osteoporosis associated with increased bone remodeling and low bone mass.     

Prevalence of vitamin D insufficiency in postmenopausal south Indian women

Aim: To evaluate the dietary calcium and vitamin D status in south Indian postmenopausal women. Methods: Postmenopausal women (n=164) were evaluated for their daily dietary calcium intake, phytate to calcium ratio, and bone mineral parameters. Their serum leutinizing hormone (LH), follicle-stimulating hormone (FSH), 25-hydroxyvitamin D (25[OH]D), and parathyroid hormone levels (PTH) were measured. Results: Their age and BMI were 59.5 ± 8 years and 27 ± 5 kg/m², respectively. Their daily dietary intake of calcium was 323 ± 66 mg/day; phytate to calcium ratio, 0.56±0.1; LH, 26 ± 13.5 µIU/l; and FSH, 62.6 ± 30 µIU/l. Their dietary intake of calcium was low compared with the recommended daily/dietary allowance (RDA) of the Indian Council of Medical Research (ICMR) for the Indian population. Of the 164 patients studied, based on population-based reference values, 126 (77%) had normal 25(OH)D levels (9–37.6 ng/ml), and 38 (23%) had 25(OH)D deficiency. Using functional health-based reference values, 30 (18%) patients had normal 25(OH)D levels (>20 ng/ml), 85 (52%) had 25(OH)D insufficiency (10–20 ng/ml), and 49(30%) had 25(OH)D deficiency (<10 ng/ml). PTH and serum alkaline phosphatase (SAP) was significantly high in patients with 25(OH)D deficiency (p<0.05) compared with those with normal 25(OH)D levels. There was a negative correlation between 25(OH)D and PTH (r=–0.2; p<0.007) and SAP (r=–0.2; p<0.001). Dietary calcium correlated positively with dietary phosphates (r=0.8; p<0.001) and phytate to calcium ratio (r=0.75; p<0.001). Conclusions: Population-based reference values underdiagnosed vitamin D insufficiency and overdiagnosed normal vitamin D status. The diet was insufficient in calcium and high in phytate. About 82% of the study group had varying degrees of low 25-hydroxyvitamin D levels. The quality of diet has to be improved with enrichment/supplementation of calcium and vitamin D to suppress secondary hyperparathyroidism-induced bone loss and risk of fractures.     

Impact of calcium and vitamin D insufficiencies on serum parathyroid hormone and bone mineral density: Analysis of the fourth and fifth Korea National Health and Nutrition Examination Survey (KNHANES IV‐3, 2009 and KNHANES V‐1, 2010)

The relative contributions of calcium and vitamin D to calcium metabolism and bone mineral density (BMD) have been examined previously, but not in a population with very low calcium intake. To determine the relative importance of dietary calcium intake and serum 25‐hydroxyvitamin D [25(OH)D] concentration to calcium metabolism and bone mass in a population with low calcium intake, a total of 4662 adults (2567 men and 2095 women) ≥50 years of age from the 2009–2010 Korea National Health and Nutrition Examination Survey (KNHANES) were divided into groups according to dietary calcium intakes (quintiles means: 154, 278, 400, 557, and 951 mg/d) and serum 25(OH)D concentrations (<50, 50–75, and >75 nmol/L). Serum intact parathyroid hormone (PTH) and femoral neck and lumbar spine BMD were evaluated according to dietary calcium intake and serum 25(OH)D. Mean calcium intake was 485 mg/d; mean serum 25(OH)D concentration was 48.1 nmol/L; PTH was 68.4 pg/mL; femoral neck BMD was 0.692 g/cm²; and lumbar spine BMD was 0.881 g/cm². Lower dietary calcium intakes were significantly associated with higher serum PTH concentrations and lower femoral neck BMD, not only at lower (<50 nmol/L) but also at higher (>75 nmol/L) serum 25(OH)D concentrations. Serum PTH was highest and femoral neck BMD was lowest in the group, with a serum 25(OH)D less than 50 nmol/L. In this low‐intake population, calcium intake is a significant determinant of serum PTH and BMD at higher as well as lower 25(OH)D levels. This finding indicates that low calcium intake cannot be compensated for with higher 25(OH)D levels alone. As expected, serum 25(OH)D levels were inversely associated with serum PTH and BMD. A calcium intake of at least 668 mg/d and a serum 25(OH)D level of at least 50 nmol/L may be needed to maintain bone mass in this calcium deficient population. © 2013 American Society for Bone and Mineral Research.     

Dietary Calcium and Serum 25‐Hydroxyvitamin D Status in Relation to BMD Among U.S. Adults

A higher calcium intake is still the primary recommendation for the prevention of osteoporosis, whereas vitamin D deficiency is often not addressed. To study the relative importance of dietary calcium intake and serum 25‐hydroxyvitamin D [25(OH)D] status in regard to hip BMD, 4958 community‐dwelling women and 5003 men ≥20 yr of age from the U.S. NHANES III population‐based survey were studied. Calcium supplement users and individuals with a prior radius or hip fracture were excluded. We calculated standardized means for BMD by quartiles of sex‐specific calcium intake for three 25(OH)D categories (<50, 50–74, and 75+ nM) among men and women, separately controlling for other important predictors of BMD. A higher calcium intake was significantly associated with higher BMD (p value for trend: p = 0.005) only for women with 25(OH)D status <50 nM, whereas calcium intake beyond the upper end of the lowest quartile (>566 mg/d) was not significantly associated with BMD at 25(OH)D concentrations >50 nM. Among men, there was no significant association between a higher calcium intake beyond the upper end of the lowest quartile (626 mg/d) and BMD within all 25(OH)D categories. Among both sexes, BMD increased stepwise and significantly with higher 25(OH)D concentrations (<50, 50–74, 75+ nM; p value for trend: women < 0.0001; men = 0.0001). Among men and women, 25(OH)D status seems to be the dominant predictor of BMD relative to calcium intake. Only women with 25(OH)D concentrations <50 nM seem to benefit from a higher calcium intake.     

Bone status of Indian women from a low-income group and its relationship to the nutritional status

Indian women from low-income groups consume diets that have inadequate calcium coupled with too few calories, proteins and micronutrients. Hospital-based data suggest that these women have osteoporotic hip fractures at a much earlier age than Western women. Studies reporting bone parameters of the Indian population involving large sample sizes are not available. This study was therefore carried out with 289 women in the 30–60-year age group to estimate the prevalence of osteoporosis and measure the bone parameters by dual energy X-ray absorptiometry (DXA). Their mean (± SD) age was 41.0±8.60 years. Their mean (± SD) height, weight and body mass index (BMI) were 149.1±5.49 cm, 49.2±9.85 kg and 22.1±3.99, respectively. Dietary intake of calcium was estimated to be 270±57 mg/day. The prevalence of osteoporosis at the femoral neck was around 29%. Bone mineral density (BMD) and T scores at all the skeletal sites were much lower than the values reported from the developed countries and were indicative of a high prevalence of osteopenia and osteoporosis. BMD showed a decline after the age of 35 years in cases of the lumbar spine and femoral neck. This was largely due to a decrease of bone mineral content (BMC). The nutritional status of women appears to be an important determinant of bone parameters. BMD and BMC at all the skeletal sites and whole body increased significantly with increasing body weight and BMI of women (P<0.05). However, bone area (BA) did not change with an increase in BMI. In the multiple regression analysis, apart from body weight, age, menopause and calcium intake were the other important determinants of BMD (P<0.05). In addition to these, height was also an important determinant of WB-BMC. This study highlights the urgent need for measures to improve the nutritional status, dietary calcium intake and thus the bone health of this population.All the authors were affiliated with the National Institute of Nutrition during the study period.     

Recovery of Bone Mineral Density in 126 Patients after Surgery for Primary Hyperparathyroidism

Primary hyperparathyroidism (pHPT) is associated with increased fracture risk and decreased bone mass. The recovery of bone mass after surgery varies; therefore tests that predict the increase in bone mass after parathyroidectomy would be desirable. Preoperatively and at 1 year after surgery bone mineral content (BMC) in the distal radius and bone mineral density (BMD) in the lumbar spine and hip, as well as biochemical variables, were measured in 126 pHPT patients (95 women, 31 men). The mean ± SD age of the patients was 63 ± 15 years. The mean ± SD serum calcium level was 2.78 ± 0.16 mmol/L. Altogether, 60% of the patients had a low oral calcium intake, and 18% had a 25-hydroxyvitamin D₃ deficiency. Preoperatively, postmenopausal women had lower Z-scores for BMD in the hip (p < 0.001) and lumbar spine (p < 0.05) than did premenopausal women. One year after surgery the bone density had increased in about 50% of the patients. The multiple logistic regression analysis showed that there was a weak association between the change in BMD in the hip, the serum 1,25-dihydroxyvitamin D₃ level (p < 0.05), and renal function (p < 0.05), respectively. We concluded that about 50% of patients have increased bone mass after pHPT surgery, but the increase in the bone density is difficult to predict for the individual patient. Because many pHPT patients have low oral calcium intake and a vitamin D deficiency, it would be of interest to evaluate the role of postoperative calcium/vitamin D supplements.     

The impact of lifestyle factors on serum 25-hydroxyvitamin D levels: a cross-sectional study in Japanese women aged 19–25 years

Insufficient levels of serum 25-hydroxyvitamin D [25(OH)D] lead to low bone mineral density (BMD) by increasing serum levels of intact parathyroid hormone (PTH), and are associated with a high mortality rate. Therefore, the 25(OH)D level is used as an indicator of frailty in older persons. To obtain higher serum 25(OH)D levels, management of lifestyle habits and nutrient intake is important beginning in a person's younger years. This study evaluated the degree of association between serum 25(OH)D concentrations and lifestyle factors in young Japanese women. A cohort study was conducted from December 2003, and the survey was finished by February 2004. The subjects were 274 Japanese women aged 19–25 years old. The parameters evaluated in these subjects included: (1) serum concentrations of 25(OH)D, intact PTH, calcium, and phosphorus; (2) BMD in the lumbar spine and hip; and (3) lifestyle factors (nutrient intake, physical activity, and duration of sunlight exposure). The serum 25(OH)D level was negatively associated with the intact PTH level (Spearman; r = –0.17, P = 0.006). The BMD was significantly higher in the high 25(OH)D and low intact PTH group than the other group (P < 0.05). The serum 25(OH)D level was significantly correlated with daily intake of dietary vitamin D (r = 0.20, P = 0.001), the mean number of steps taken per day (r = 0.16, P = 0.010) and the mean time spent in sedentary activity (r = –0.14, P = 0.018) among the lifestyle factors evaluated. Multiple regression analysis showed the degree of association between lifestyle factors and serum 25(OH)D to be small (R ² = 0.084). Daily intake of dietary vitamin D and daily walking may be useful for increasing the serum 25(OH)D level in young Japanese women.     

Prevalence of Vitamin D Insufficiency and Deficiency in Morbidly Obese Patients: A Comparison with Non-Obese Controls

Background Vitamin D deficiency is common in patients after bariatric surgery. However, obesity itself has also been associated with decreased vitamin D. The prevalence of vitamin D deficiency in obese persons has not previously been compared to non-obese controls when controlling for factors that could affect vitamin D status. Methods We evaluated 25 hydroxy vitamin D, iPTH, calcium, albumin, and creatinine in 41 patients undergoing Roux-en-Y gastric bypass. We then compared them to healthy non-obese controls matched for age, sex, race/ethnicity, and season of vitamin D measurement. Results Ninety percent of the pre-bariatric surgery patients had 25-OH-D levels <75 nmol/l, and 61% had 25-OH-D levels <50 nmol/l versus 32 and 12% in controls, respectively. Additionally, 49% of the pre-bariatric surgery patients had secondary hyperparathyroidism versus 2% of controls. These differences persisted after controlling for sunlight exposure and dietary intake of calcium and vitamin D. Mean calcium, corrected for albumin, and creatinine were not significantly different between the groups, but mean albumin levels were significantly lower among surgery patients. Conclusion Vitamin D deficiency is common in obese patients at the time of bariatric surgery and is also accompanied by secondary hyperparathyroidism approximately half the time. These findings suggest that vitamin D deficiency after bariatric surgery is multifactorial and in part caused by preoperative vitamin D deficiency rather than postoperative malabsorption alone. In this study, increased vitamin D deficiency in obese persons cannot be explained by a difference in calcium/vitamin D intake or sunlight exposure.     

Monthly ibandronate for the prevention of bone loss in patients after liver transplantation

Background

Osteopenia and osteoporosis are diseases frequently occurring after liver transplantation (OLT).

Purpose

In a prospective study, we have investigated the effect of ibandronate, vitamin D₃, and calcium on the prevention and treatment of posttransplant osteopenia and osteoporosis.

Methods

The bone mineral density (BMD) of the lumbar spine (LS) and of the femoral neck (FN) were measured in 74 patients prospectively pre- and post-OLT.

Results

Postoperatively the study group showed a consistent percentage increase in BMD (g/cm²) and a significantly increased BMD after 12 and 24 months in the LS (12 months: 1.05 ± 0.21 g/cm²; P < .001 24 months: 1.11 ± 0.19 g/cm²; P < .001) and the FN (12 months: 0.88 ± 0.16 g/cm²; P < .002 24 months: 0.90 ± 0.15 g/cm²; P < .001) in comparison with baseline pre-OLT (LS pre-OLT 0.98 ± 0.19 g/cm², FN 0.86 ± 0.14 g/cm²). The overall bone fracture rate was 5.4% up to 24 months.

Conclusion

Ibandronate once monthly per os significantly increased the BMD in the LS and FN after OLT at 12 and 24 months. The increased BMD limits the risk of fracture.     

Bone Mineral Density of the Spine and Femur in Healthy Saudi Females: Relation to Vitamin D Status, Pregnancy, and Lactation

Bone mineral density (BMD) measurements of the anterio-posterior lumbar spine and the proximal femur using dual-energy x-ray absorptiometry, as well as relevant clinical and biochemical parameters, were determined in 321 healthy Saudi females in order to establish reference values and to study the effects of physical and lifestyle factors on BMD. Mean ± SD of age, body mass index (BMI), number of pregnancies, and total duration of lactation were 35.4 ± 11.3 years, 26.5 ± 5.2 kg/m², 3.1 ± 3.1, and 23.7 ± 42.4 months, respectively. Mean ± SD of serum calcium, 25-hydroxyvitamin D (25OHD), and PTH levels were 2.37 ± 0.09 mmol/liter, 24.5 ± 17.2 nmol/liter, and 52.0 ± 30.8 pg/ml, respectively. Peak BMD values were observed around age 35 years at the spine and earlier at the femur. Compared with USA females, Saudi females had lower weight-matched Z scores at the spine (−0.126 ± 1.078, P= 0.04), femoral neck (−0.234 ± 0.846, P < 0.0001), and Ward's triangle (−0.269 ± 1.015, P < 0.0001). Further, the prevalence of osteopenia and osteoporosis in subjects ≥31 years old were 18–41% and 0–7%, respectively, depending on the site examined. Severe hypovitaminosis D (25OHD level ≤20 nmol/liter) was present in 52% of the subjects. However, there was no correlation between 25OHD level and BMD at any site. Parathyroid hormone (PTH) levels correlated significantly with 25OHD levels (r =−0.28, P < 0.0001) and with weight-matched BMD Z scores at the spine (r =−0.17, P= 0.005), femoral neck (r =−0.16, P= 0.007), and Ward's triangle (r =−0.2, P= 0.0008), suggesting that the distribution of 25OHD levels in the cohort is below the threshold needed for maintaining normal BMD. On the other hand, number of pregnancies and total duration of lactation correlated with weight-matched BMD Z scores at the spine (r =−0.17, P= 0.003; r =−0.1, P= 0.08, respectively). We conclude that BMD in healthy Saudi females is significantly lower than in their USA counterparts. This may be due in part to increased number of pregnancies and longer duration of lactation together with prevalent vitamin D deficiency. Received: 21 July 1998 / Accepted: 1 November 1998     

Low Sit-to-Stand Performance is Associated with Low Femoral Neck Bone Mineral Density in Healthy Women

Bone mass may be adjusted to control the strains produced by muscular activity. We assessed the relationship between maximum rising strength (MRS), a new measurement of sit-to-stand performance, and femoral neck (FN) bone mineral density (BMD), taking into account possible confounding variables. The study population consisted of 249 healthy women aged 18–76. We measured MRS with a dynamometer fixed on the ground and connected by an adjustable nonelastic cord to a padded belt. FN BMD was measured by dual X-ray absorptiometry. Women in the first quartile of FN BMD (<0.702 g/cm²) had significantly lower values of MRS, body weight, height, lean mass, past 5-year physical activity expenditures, blood 17 beta estradiol (E2), 25-hydroxyvitamin D (25(OH)D), dehydroepiandrosterone sulfate (DHEAS), and insulin like growth factor 1, and higher values of age and parathyroid hormone than other women. In the logistic regression model, FN BMD values in the lowest quartile were associated with age (adjusted odds ratio [OR_a] per 10-year increase = 1.84, 95% confidence interval [95% CI] = 1.33–2.54, P < 0.001), body weight (OR_a per 10-kg decrease = 3.67, 95% CI = 2.08–6.47, P < 0.001), MRS (OR_a per 20-kg decrease = 1.17, 95% CI = 1.02–1.34, P = 0.03), serum DHEAS (OR_a < 0.5 mg/ml vs ≥0.5 mg/ml = 2.83, 95% CI = 1.3–6.12, P = 0. 01), and serum E2 (OR_a per 10-pmol/l decrease = 1.02, 95% CI = 1.01–1.03, P = 0.03). The present study suggests a significant association between low FN BMD and low sit-to-stand performance in healthy women, independent of possible confounding variables.     

Influence of PTH and 1,25(OH)2D on calcium homeostasis and bone mineral content after gastric surgery

Summary In 57 patients surgically treated for ulcer, we found low 25OHD concentrations, elevated 1,25(OH)₂D concentrations, (P<0.001), a normal iPTH level, and a not significantly reduced bone mineral content (BMC) measured by single photon absorptiometry. The 25OHD concentrations were highest in patients regularly taking tablets containing vitamin D (P<0.05), whereas the 1,25 (OH)₂D concentrations and the BMC values were not affected by vitamin D intake. The most severe calcium metabolic disturbances were seen in 15 Billroth I resected patients whose BMC was 89.4±12.4% of normal. Although the dietary intake of calcium and vitamin D complied with the Scandinavian recommendations and calcium absorption was in the lower part of the normal range, the general state of nutrition appears to influence the bone mass of such patients. In the patients as a group, the 1,25(OH)₂D concentrations were significantly related to BMC (r=0.42,P<0.001) and biochemical signs of bone resorption (r=0.68,P<0.001) and formation (r=0.42,P<0.001) Conversely, no relationship could be detected between serum iPTH and bone mass or bone turnover. We suggest that the high 1,25(OH)₂D concentrations found after gastric resections express a compensatory process leading to an increase in calcium absorption, and that the initial event in this sequence is a trend toward low serum calcium levels. With increased demands on this regulation or lack of precursor for 1,25(OH)₂D synthesis, bone mass declines through the action of 1,25(OH)₂D and/or PTH.     

Increased Serum 1,25-Dihydroxyvitamin D after Growth Hormone Administration is not Parathyroid Hormone-Mediated

To assess the effects of growth hormone (GH) on serum 1,25-dihydroxyvitamin D [1,25(OH)₂D], we performed the following prospective crossover study in six healthy, young, adult, white men. During each of two admissions for 2? days to a general clinical research center, subjects were placed on a daily dietary calcium intake of 400 mg. Serum calcium, phosphorus, 1,25(OH)₂D, immunoreactive intact parathyroid hormone (PTH), insulin-like growth factor I (IGF-I), IGF binding protein 3 (IGFBP3), tubular reabsorption of phosphate (TRP), and maximum tubular reabsorption of phosphate (TMP/GFR) were measured. Recombinant human GH (rhGH, Humatrope) (25 μg/kg/day subcutaneously for 1 week) was administered prior to and during one of the admissions. Results are expressed as mean ± SEM. Whereas serum 1,25(OH)₂D (58.9 ± 7.7 versus 51.6 ± 7.4 pg/ml, P < 0.01), serum phosphorus (4.5 ± 0.1 versus 3.7 ± 0.1 mg/dl, P < 0.01), TRP (92.0 ± 0.5 versus 87.8 ± 0.7 mg/dl, P < 0.005), TMP/GFR (4.6 ± 0.1 versus 3.5 ± 0.2, P < 0.005), and urinary calcium (602 ± 49 versus 346 ± 25 mg/day, P < 0.001) increased significantly, serum PTH decreased significantly (19.9 ± 1.9 versus 26.8 ± 4.0 pg/ml, P < 0.05) and serum calcium did not change when subjects received rhGH. These findings indicate that in humans, GH affects serum 1,25(OH)₂D independently of circulating PTH and that this effect is mediated by IGF-I. We propose, therefore, that one potential mechanism by which GH stimulates increases in bone mass is via modest increases in serum 1,25(OH)₂D. Received: 2 May 1996 / Accepted: 18 October 1996     

Exercise frequency and calcium intake predict 4-year bone changes in postmenopausal women

The aim of this study was to examine the association of exercise frequency and calcium intake (CI) with change in regional and total bone mineral density (BMD) in a group of postmenopausal women completing 4 years of progressive strength training. One hundred sixty-seven calcium-supplemented (800 mg/day) sedentary women (56.1±4.5 years) randomized to a progressive strength training exercise program or to control were followed for 4 years. Fifty-four percent of the women were using hormone therapy (HT) at baseline. At 1 year, controls were permitted to begin the exercise program (crossovers). The final sample included 23 controls, 55 crossovers, and 89 randomized exercisers. Exercisers were instructed to complete two sets of six to eight repetitions of exercises at 70–80% of one repetition maximum, three times weekly. BMD was measured at baseline and thereafter annually using dual-energy X-ray absorptiometry. Four-year percentage exercise frequency (ExFreq) averaged 26.8%±20.1% for crossovers (including the first year at 0%), and 50.4%±26.7% for exercisers. Four-year total CI averaged 1,635±367 mg/day and supplemental calcium intake, 711±174 mg/day. In adjusted multiple linear regression models, ExFreq was positively and significantly related to changes in femur trochanter (FT) and neck (FN), lumbar spine (LS), and total body (TB) BMD. Among HT users, FT BMD increased 1.5%, and FN and LS BMD, 1.2% ( p <0.01) for each standard deviation (SD) of percentage ExFreq (29.5% or 0.9 days/week). HT non-users gained 1.9% and 2.3% BMD at FT and FN, respectively, ( p <0.05) for every SD of CI. The significant, positive, association between BMD change and ExFreq supports the long-term usefulness of strength training exercise for the prevention of osteoporosis in postmenopausal women, especially HT users. The positive relationship of CI to change in BMD among postmenopausal women not using HT has clinical implications in light of recent evidence of an increased health risk associated with HT.     

The Relation of Dietary Vitamin C Intake to Bone Mineral Density: Results from the PEPI Study

Ascorbic acid is a required cofactor in the hydroxylations of lysine and proline necessary for collagen formation; its role in bone cell differentiation and formation is less well characterized. This study examines the cross-sectional relation between dietary vitamin C intake and bone mineral density (BMD) in women from the Postmenopausal Estrogen/Progestin Interventions Trial. BMD (spine and hip) was measured using dual energy X-ray absorptiometry (DXA). The PEPI participants (n = 775) included in this analysis were Caucasian and ranged in age from 45 to 64 years. At the femoral neck and total hip after adjustment for age, BMI, estrogen use, smoking, leisure physical activity, calcium and total energy intake, each 100 mg increment in dietary vitamin C intake, was associated with a 0.017 g/cm² increment in BMD (P= 0.002 femoral neck; P= 0.005 total hip). After adjustment, the association of vitamin C with lumbar spine BMD was similar to that at the hip, but was not statistically significant (P= 0.08). To assess for effect modification by dietary calcium, the analyses were repeated, stratified by calcium intake (>500 mg/day and ≤500 mg/day). For the femoral neck, women with higher calcium intake had an increment of 0.0190 g/cm² in BMD per 100 mg vitamin C (P= 0.002). No relation between BMD and vitamin C was evident in the lower calcium stratum. Similar effect modification by calcium was observed at the total hip: the β coefficient in the higher calcium stratum was similar to that for the total sample (β= 0.0172, P= 0.01), but no statistically significant relation between total hip BMD and vitamin C was found in the lower calcium subgroup. Although the relation between vitamin C and lumbar spine BMD was of marginal statistical significance in the total sample, among women ingesting higher calcium, a statistically significant association was observed (β= 0.0199, P= 0.024). These data are consistent with a positive association of vitamin C with BMD in postmenopausal women with dietary calcium intakes of at least 500 mg. Received: 12 September 1997 / Accepted: 27 January 1998     

Prophylactic calcium and vitamin D treatments in steroid-treated children with nephrotic syndrome

Steroid treatment has several side effects, including the deterioration of the bone and mineral metabolism in children with nephrotic syndrome. This randomized prospective study was conducted to determine the effects and prophylactic role of calcium plus vitamin D treatment on bone and mineral metabolism in children receiving prednisolone treatment. 40 children (27 boys and 13 girls) with NS (18 new onset and 22 relapsing) were included in the study. Their mean age was 4.6±1.8 years. All patients received prednisolone treatment (2 mg/kg/day for 4 weeks followed by alternate days at the same dose for 4 weeks). The patients were randomized into treatment (vitamin D 400 IU plus calcium 1 g daily) and non-treatment groups. Bone mineral density, serum Ca, P, alkaline phosphatase and urinary Ca and P excretions were analyzed at the beginning and 2 months after the treatment. The XR36 Norland device was used for bone mineral density analysis. Bone mineral density was significantly decreased in both the treatment (0.54±0.15 to 0.51±0.1 g/cm², P =0.001) and non-treatment (0.52±0.18 to 0.45±0.16 g/cm², P <0.001) group. But the percentage of bone mineral density decrease was found to be significantly lower in the treatment group than in the non-treatment group (4.6±2.1% vs. 13.0±4.0%, respectively; P <0.001). Serum calcium and urinary calcium excretion increased in the treatment group (8.0±1.0 to 10.0±0.5 mg/dl and 1.1±0.5 to 3.2±1.0 mg/kg/day) and non-treatment group (8.1±0.8 to 10.0±0.6 mg/dl and 1.4±0.9 to 3.8±3.3 mg/kg/day) after prednisolone treatment (P <0.001). Steroid treatment decreases bone mineral density in children with nephrotic syndrome. Vitamin D plus calcium therapy at the current doses reduces but does not completely prevent bone loss, with no additional adverse effects.     

Bone mineral density in men with genetic hemochromatosis and HFE gene mutation

Genetic hemochromatosis (GH) is an iron overload disorder mainly due to the C282Y mutation of the HFE gene. The possibility of bone involvement was only recently recognized. The aims of this study were to assess bone mineral density (BMD) and bone remodeling in men with GH, and to examine the influence of iron overload. Thirty-eight men (mean age 47.2±9.4 years) with well-defined HFE-related GH were studied. They had an important iron overload with liver iron concentration to age ratio >2.5, no previous venesection therapy and were C282Y homozygotes ( n =37) or compound C282Y/H63D heterozygote ( n =1). BMD measured by DXA was 0.925±0.15 g/cm² at the lumbar spine (LS) and 0.778±0.13 g/cm² at the femoral neck (FN). Osteopenia (T-score <–1 SD) was observed in 78.9% of patients and osteoporosis (T-score <–2.5 SD) in 34.2%. Vitamin D levels were normal, and no 1–84 parathyroid hormone dysfunction was found. Hypogonadism was found in only 13.2% of patients. Patients with hypogonadism had lower LS BMD than eugonadal patients (0.788±0.16 and 0.954±0.14 g/cm²). Bone remodeling and parathyroid hormone levels were lower in patients with cirrhosis, but BMD values were similar to those in patients without cirrhosis. FN BMD appeared to fall with rising hepatic iron concentrations ( r =–0.399). We conclude that there is significant bone loss in HFE-related hemochromatosis that cannot solely be explained by hypogonadism or cirrhosis. Further investigations are needed to determine the role of iron overload itself.