Postmenopausal osteoporosis and the detection of so-called secondary causes of low bone density

Celiac disease and primary hyperparathyroidism

OBJECTIVE

Primary hyperparathyroidism (PHPT) and celiac disease (CD) are two distinct medical conditions that can affect bone health. While PHPT leads to excessive calcium levels and bone abnormalities, CD impairs calcium and vitamin D absorption due to small intestine damage.

CASE REPORT

We present a case of a 49-year-old woman diagnosed with osteoporosis who was found to have both PHPT and CD. The patient underwent a successful minimally invasive parathyroidectomy, which resulted in decreased parathyroid hormone levels.

CONCLUSION

This case highlights the rare coexistence of PHPT and CD and emphasizes the importance of considering secondary causes of osteoporosis in patients with low bone mass. Further studies are needed to explore the underlying mechanisms and potential links between PHPT and CD.

Vitamin A intake, serum vitamin D and bone mineral density: analysis of the Korea National Health and Nutrition Examination Survey (KNHANES, 2008-2011)

The association of high vitamin A intake and low bone mineral density (BMD) is still controversial. To determine the association of dietary vitamin A intake and serum 25-hydroxyvitamin D (25(OH)D) concentration with BMD, a total of 6481 subjects (2907 men and 3574 women) aged ≥50 years from the Korean National Health and Nutrition Examination Survey (2008–2011) were divided into groups according to dietary vitamin A intake (tertiles) and serum 25(OH)D (<50, 50–75, >75 nmol/L), and evaluated for BMD after adjusting for relevant variables. Mean dietary vitamin A intakes were 737 and 600 μg RE (Retinol Equivalents) in men and women, respectively. Total hip and femoral neck BMD in men and lumbar spine BMD in women were both positively correlated with dietary vitamin A intake in subjects with serum 25(OH)D >75 nmol/L. Among men with serum 25(OH)D <50 nmol/L, both the top (mean 1353 μg RE) and bottom (mean 218 μg RE) tertiles of dietary vitamin A intake had lower BMD than the middle group (mean 577 μg RE). In this population, BMD was the highest among men and women with serum 25(OH)D = 50–75 nmol/L and that there were no differences in BMD by vitamin A intake in these vitamin D adequate groups. This cross-sectional study indicates that vitamin A intake does not affect bone mineral density as long as the serum 25(OH)D concentration is maintained in the moderate level of 50–75 nmol/L.

The Relationship between Serum 25-Hydroxyvitamin D, Parathyroid Hormone and the Glomerular Filtration Rate in Korean Adults: The Korea National Health and Nutrition Examination Survey between 2009 and 2011

BACKGROUND

The glomerular filtration rate (GFR) decreases with age, while parathyroid hormone (PTH) increases. There are a few reports only on the relationship between GFR and PTH under the category of serum 25-hydroxyvitamin D (25[OH]D) concentration.

METHODS

Using the Korea National Health and Nutrition Examination Survey (KNHANES) data, a cross-sectional study was conducted on the association between serum 25(OH)D concentration, GFR and PTH in Korean adults aged 50 years or older. Serum PTH concentration was compared to the tertiles of GFR after adjustment for relevant variables. In addition, the serum PTH concentration was compared with the GFR under the category of serum 25(OH) D concentration (<20, 20-30, >30 ng/mL).

RESULTS

The mean estimated GFR (eGFR) was 74.8 mL/min in men and 73.1 mL/min in women. The mean PTH and 25(OH) D was 66.8 pg/mL, 20.5 ng/mL in men and 69.0 pg/mL, 18.2 ng/mL in women. The serum PTH concentration showed a significant negative correlation with the serum 25(OH) D and eGFR in both genders. The serum PTH concentration significantly increased at the lower tertile of eGFR in male adults In addition, a decrease of serum PTH concentration was marked in the vitamin D sufficient male adults (>30 ng/mL).

CONCLUSION

This present study demonstrated that serum PTH concentration showed negative correlation with eGFR, however, serum PTH increase may be minimized by maintaining proper serum 25(OH)D concentrations under similar eGFR status in Korean adults aged 50 and above.

Management of skeletal health in patients with asymptomatic primary hyperparathyroidism

Asymptomatic primary hyperparathyroidism (PHPT) may cause adverse skeletal effects that include high bone remodeling, reduced bone mineral density (BMD), and increased fracture risk. Parathyroid surgery, the definitive treatment for PHPT, has been shown to increase BMD and appears to reduce fracture risk. Current guidelines recommend parathyroid surgery for patients with symptomatic PHPT or asymptomatic PHPT with serum calcium >1mg/dL above the upper limit of normal, calculated creatinine clearance <60 mL/min, osteoporosis, previous fracture, or age <50 yr. The type of operation performed (parathyroid exploration or minimally invasive procedure) and localizing studies to identify the abnormal parathyroid glands preoperatively should be individualized according to the skills of the surgeon and the resources of the institution. In patients who choose not to be treated surgically or who have contraindications for surgery, medical therapy should include a daily calcium intake of at least 1200 mg and maintenance of serum 25-hydroxyvitamin D levels of at least 20 ng/mL (50 nmol/L). Bisphosphonates and estrogens have been shown to provide skeletal benefits that appear to be similar to parathyroid surgery. Cinacalcet reduces serum calcium in PHPT patients with intractable hypercalcemia but has not been shown to improve BMD. It is not known whether any medical intervention reduces fracture risk in patients with PHPT. There are insufficient data on the natural history and treatment of normocalcemic PHPT to make recommendations for management of this disorder.

Vitamin D status in psoriasis patients during different treatments with phototherapy

BACKGROUND

Phototherapy (broadband UVB (BUVB), narrowband UVB (NBUVB) and heliotherapy) is commonly used treatment modalities for widespread psoriasis. Vitamin D3, cholecalciferol, is produced in the epidermis by ultraviolet radiation (290-315 nm) of 7-dehydrocholesterol. 25-hydroxyvitamin D [25(OH)D], and 1,25-dihydroxyvitamin D [1,25(OH)(2)D] are the major circulating metabolites. Sun exposure is the strongest factor influencing 25(OH)D. The similar wavelength spectrum of UVB responsible for D vitamin synthesis (BUVB, 280-315 nm) has been successfully used for years to treat psoriasis.

PURPOSE

The aim was: (1) To increase the knowledge about the effects of phototherapy on vitamin D production during treatment of psoriasis. (2) To examine if there were differences between the effect of BUVB, NBUVB and heliotherapy on vitamin D synthesis in psoriasis patients.

METHODS

Serum concentrations of 25(OH)D, 1,25(OH)(2)D, PTH, calcium and creatinine, measured before and after phototherapy in white Caucasian patients with moderate to severe active plaque psoriasis, were aggregated from three studies.

RESULTS

Psoriasis improved in all patients, with a reduction in PASI ((Psoriasis Area and Severity Index) score of about 75% on all regimes. Serum 25(OH)D increased and PTH decreased after the phototherapy. The increase in 25(OH)D was higher in the BUVB treated patients compared with NBUVB. There was no correlation between the dose of UVB and the increase of 25(OH)D.

CONCLUSION

UVB and heliotherapy improved the psoriasis score, increased the serum 25(OH)D levels and reduced the serum PTH concentrations. Vitamin D production in psoriasis patients increased less with NBUVB than with BUVB phototherapy.

Evaluation of secondary causes of bone loss in a primary care setting

OBJECTIVE

To evaluate the clinical and laboratory work-up for secondary causes of bone loss in a primary care setting.

METHODS

We conducted a retrospective review of medical records of 100 patients with either osteoporosis or osteopenia, who presented to a university-based primary care clinic. Patients with chronic kidney disease or a history of organ transplantation were excluded, as were premenopausal women.

RESULTS

Age at menopause was ascertained in 43% of female patients. Only 2% of patients were asked specifically about symptoms of malabsorption, whereas a history of malignant disease or its treatment was elicited from 24%. Of the overall study group, 50% were asked about a history of thyroid disease and 18% about a history of liver disease. Testicular examination was documented in 40% of male patients. Serum calcium and creatinine, complete blood cell count, and thyroid function tests were evaluated in 100% of patients. Vitamin D status was assessed in only 1 patient; no study patient had a 24-hour urine collection for determination of calcium excretion. Serum parathyroid hormone was measured in 7% and serum phosphorus in 10% of patients. Sixty percent of male patients had their testosterone levels assessed. Although the serum creatinine level was determined in all patients, only 1% had a formal estimation of the creatinine clearance or glomerular filtration rate.

CONCLUSION

The evaluation of secondary causes of bone loss was notably inadequate in our study population. Because most patients with osteoporosis or osteopenia are managed in the primary care setting, a distinct need exists for consensus guidelines and recommendations from professional endocrine organizations to advise primary care physicians in the appropriate diagnostic evaluation for secondary causes of bone loss in such patients.

Increase in bone mass after correction of vitamin D insufficiency in bisphosphonate-treated patients

OBJECTIVE

To assess the relative contribution of vitamin D insufficiency to loss of bone mineral density (BMD) in patients taking bisphosphonates.

METHODS

Patients were eligible for inclusion if they had osteoporosis or osteopenia and demonstrated a decline in BMD during the preceding year while taking stable doses of alendronate or risedronate, plus supplemental calcium and vitamin D. Patients with previously known secondary causes of osteoporosis were excluded from the study. Eligible patients underwent prospective measurement of bilateral hip and lumbar spine BMD by dual-energy x-ray absorptiometry, serum 25-hydroxyvitamin D (25-OHD), 1,25-dihydroxyvitamin D, intact parathyroid hormone, osteocalcin, and thyroid-stimulating hormone (thyrotropin), and urinary calcium:creatinine ratio.

RESULTS

Annual BMD was assessed in 175 previously bisphosphonate-responsive patients with low BMD. Of the 175 patients, 136 (78%) had either a significant interval increase or no change in BMD, whereas 39 (22%) had a significant decrease. Of the 39 patients who lost BMD, 20 (51%) had vitamin D insufficiency (25-OHD <30 ng/mL). After a single course of orally administered vitamin D2 (500,000 IU during a 5-week period), the 25-OHD level returned to normal in 17 of the 20 vitamin D-insufficient patients and was associated with significant (P<.02) 3.0% and 2.7% increases in BMD at the lumbar spine and the femoral neck, respectively. Failure to normalize the serum 25-OHD level was associated with further loss of BMD.

CONCLUSION

Vitamin D insufficiency was the most frequently identified cause of bone loss in patients with declining BMD during bisphosphonate therapy. Correction of vitamin D insufficiency in these patients led to a significant rebound in BMD.

Intestinal hyperabsorption of calcium and low bone turnover in hypercalciuric postmenopausal osteoporosis

Hypercalciuria of intestinal origin has been linked with bone loss in calcium nephrolithiasis and idiopathic osteoporosis. This retrospective data analysis was performed to explore potential pathogenetic link between intestinal hyperabsorption of calcium and postmenopausal osteoporosis. Data were retrieved from postmenopausal women who were evaluated for osteoporosis or osteopenia at the Mineral Metabolism Clinic of UT Southwestern Medical Center. A total of 319 patients underwent the test of calciuric response to oral calcium load to obtain an indirect measure of intestinal calcium absorption. Serum and urinary biochemistry and L2-L4 bone mineral density (BMD) were compared between five quintiles of calciuric response. There was a statistically significant trend toward a rise in 24-h urinary calcium and a decrease in urinary deoxypyridinoline (DPD) and BMD, with increasing order of quintiles. The presentation of those in the 1st quintile was consistent with vitamin D insufficiency or deficiency, with impaired calcium absorption, secondary hyperparathyroidism, and stimulated bone turnover (high normal urinary DPD). In contrast, patients in the 5th quintile displayed a picture of absorptive hypercalciuria of stone disease, with intestinal hyperabsorption of calcium, high or high normal urinary calcium and suppressed bone turnover (low or low normal urinary DPD). Thus, the assessment of intestinal calcium absorption in a seemingly homogeneous group of postmenopausal women with osteoporosis or osteopenia revealed a spectrum of calciuric response whose extremes may represent two physiologically distinct subtypes that have important diagnostic and therapeutic implications.

Secondary contributors to bone loss in osteoporosis related hip fractures

Osteoporosis treatment of patients with hip fractures is necessary to prevent subsequent fractures. Secondary causes for bone loss are present in more than 80% of patients with hip fractures, and therefore, assessment of Vitamin D status, disorders in calcium absorption and excretion, monoclonal gammopathies, and renal function should be performed. Identifying and managing these disorders will improve detection and enhance treatment aimed at reducing the risk of recurrent fractures in older adults.

INTRODUCTION

The purpose of this study was to determine the prevalence of disorders affecting bone and mineral metabolism in individuals with osteoporotic hip fractures.

METHODS

Community dwelling individuals with hip fractures (HFx) 50 years of age and older. Assessment for vitamin D, renal and parathyroid status, calcium absorption, and plasma cell disorders.

RESULTS

Of 157 HFx, mean age 70 +/- 10 years, HFx had higher creatinine (p = 0.002, 95% C.I. -0.09, 0.05); lower 25 OH vitamin D (p = 0.019, 95% C.I. 6.5, 2.7), albumin (p = 0.007, 95% C.I. 0.36, 0.009), and 24-h urine calcium (p = 0.024, 95% CI 51, 21) as compared to controls. More than 80% of HFx had at least one previously undiagnosed condition, with vitamin D insufficiency (61%), chronic kidney disease (16%) (CKD), monoclonal gammopathy (6%), and low calcium absorption (5%) being the most common. One case each of multiple myeloma and solitary plasmocytoma were identified.

CONCLUSIONS

Osteoporosis treatment of HFx is necessary to prevent subsequent fractures. Secondary causes for bone loss are remarkably common in HFx; therefore, assessment of vitamin D status, disorders in calcium absorption and excretion, protein electrophoresis, and renal function should be performed. Identifying and correcting these disorders will improve detection and enhance treatment aimed at reducing the risk of recurrent fractures in older adults.

UVB therapy increases 25(OH) vitamin D syntheses in postmenopausal women with psoriasis

BACKGROUND

Vitamin D3 is produced in the epidermis by ultraviolet (UV) radiation (290-315 nm) of 7-dehydrocholesterol. A similar range of 290-320 nm (broadband UVB) has been successfully used for years to treat psoriasis. The aim of this study was to investigate whether UVB therapy was able to influence vitamin D synthesis in psoriasis patients.

METHODS

Twenty-four postmenopausal, white Caucasian women, aged 69 +/- 5.9 (mean +/- SD), with active plaque psoriasis, were treated with broadband UVB two to three times per week for 8-12 weeks. The serum concentrations of calcidiol (25(OH)D3), calcitriol (1,25(OH)2D3), intact parathyroid hormone (PTH), thyroid hormones, osteocalcin, calcium and creatinine were measured before the first and after the last dose of radiation. Bone density was measured using Dual-Energy X-ray Absorptiometry (Hologic Delphi A) at the hip and lumbar spine.

RESULTS

Serum levels of 25(OH)D3 increased from 36.8 +/- 17 ng/ml (mean +/- SD) to 59.6 +/- 18.7 ng/ml (P<0.001) after the UVB treatment period. Serum PTH decreased from 62.8 +/- 25.7 ng/l to 48.2 +/- 17.4 ng/l (P<0.001). Secondary hyperparathyroidism (PTH>65 ng/l) was revealed in seven patients (29%) in whom PTH values were suppressed by the UVB therapy. The serum levels of calcitriol, calcium, osteocalcin, thyroid hormones and creatinine were unaltered.

CONCLUSION

UVB therapy in elderly psoriatic women improved psoriasis, increased serum 25(OH)D3 synthesis and reduced serum PTH concentrations.

Patient assessment in the diagnosis, prevention, and treatment of osteoporosis

Assessment of the patient with osteoporosis includes history and physical examination, laboratory testing, and imaging studies. Information gathered during this assessment assists clinicians in targeting strategies to prevent fractures. The medical history should contain items such as personal and family history of fractures, lifestyle, intake of substances such as vitamin D, calcium, corticosteroids, and other medications. The physical examination can reveal relevant information such as height loss and risk of falls. Bone mineral density (BMD), most commonly determined by dual-energy x-ray absorptiometry, best predicts fracture risk in patients without previous fracture. BMD testing is most efficient in women over 65 years old but is also helpful for men and women with risk factors. Serial BMD tests can identify individuals losing bone mass, but clinicians should be aware of what constitutes a significant change. Laboratory testing can detect other risk factors and can provide clues to etiology. Selection of laboratory tests should be individualized, as there is no consensus regarding which tests are optimal. Biochemical markers of bone turnover have a potential role in fracture risk assessment and in gauging response to therapy, but are not widely used at present. Clinicians should be aware of problems with vitamin D measurement, including seasonal variation, variability among laboratories, and the desirable therapeutic range. Careful assessment of the osteoporotic patient is essential in developing a comprehensive plan that reduces fracture risk and improves quality of life.

Glomerular filtration rate is a major determinant of the relationship between 25-hydroxyvitamin D and parathyroid hormone

The reference range for 25-hydroxyvitamin D (25-OHD) remains uncertain, and it is not clear as to whether interpretation of circulating 25-OHD would be aided by simultaneous measurement of serum parathyroid hormone (PTH). We wanted to define the level of serum 25-OHD associated with a raised serum PTH and to examine the determinants of the relationship between serum 25-OHD and serum PTH concentration. We retrospectively examined data for patients who had a 25-OHD measurement and other biochemical variables over a 12-month period in our center. We found that 28% of patients had a serum 25-OHD level below 50 nmol/L and serum PTH level in the normal reference range, whereas 24% had a serum 25-OHD level below 50 nmol/L with a serum PTH value above the normal reference range. At a serum 25-OHD level of 80 nmol/L, 1.5% had an elevated serum PTH and, at 50 nmol/L, 8% had raised serum PTH. Further examination showed that for patients with low serum 25-OHD, low glomerular filtration rate (GFR) was a major determinant of the PTH response. These data confirm an inverse correlation between serum 25-OHD and serum PTH. Minimal numbers of patients (1.5% of the study group) have a raised serum PTH at a serum 25-OHD level of 80 nmol/L. GFR is a major determinant of the PTH response to decreasing serum levels of 25-OHD.

Secondary osteoporosis: a review of the recent evidence

OBJECTIVE

To review several causes of secondary osteoporosis as well as screening recommendations for underlying disorders.

METHODS

We conducted a review of the literature on many of the causes of osteoporosis that have been published during the past 15 years, focusing on those sources available from 2000 through the present. Indeed, more than two-thirds of the articles that we reviewed were printed during the past 6 years. These reports examined secondary osteoporosis in general, as well as many of the specific causes.

RESULTS

Secondary osteoporosis occurs in almost two-thirds of men, more than half of premenopausal and perimenopausal women, and about one-fifth of postmenopausal women. Its causes are vast, and they include hypogonadism, medications, hyperthyroidism, vitamin D deficiency, primary hyperparathyroidism, solid organ transplantation, gastrointestinal diseases, hematologic diseases, Cushing's syndrome, and idiopathic hypercalciuria. These causes have their own pathogenesis, epidemiologic features, and effect on the skeleton.

CONCLUSION

The causes of secondary osteoporosis are numerous, and an understanding of their characteristics with respect to bone density and potential fracture risk is essential in the management of osteoporosis. A heightened awareness of the possibility of their existence is necessary to provide optimal care.