Tenofovir-induced hypophosphatemic osteomalacia: how do bone mineral density, trabecular bone score and proximal hip geometry change with treatment?

Summary: Tenofovir-induced osteomalacia secondary to proximal renal tubular dysfunction is not an uncommon complication known to occur. A 46-year-old woman was referred for the evaluation of osteoporosis which was diagnosed elsewhere. She had polyarthralgia, bony pains and proximal muscle weakness of 1 year duration. She was diagnosed to have HIV infection and was on antiretroviral therapy that consisted of tenofovir, lamivudine and efavirenz for the past 12 years. She had attained menopause 5 years back. On examination, she had bone tenderness, proximal myopathy and painful restriction of movement of her lower limbs. Investigations showed features of renal tubular acidosis, hypophosphatemia and raised alkaline phosphatase that were suggestive of osteomalacia. X-ray of the pelvis showed diffuse osteopenia and an MRI of the pelvis done showed multiple insufficiency fractures involving the head of femur on both sides. Following this, her tenofovir-based regimen was changed to abacavir, efavirenz and lamivudine with addition of neutral phosphate supplements and calcitriol. On follow-up after 6 months, she had significant improvement in her symptoms as well as in the bone mineral density at the lumbar spine (33.2%), femoral neck (27.6%), trabecular bone score (13.2%) and reduction in the buckling ratio at the narrow neck (6.3%), inter-trochanteric region (34%) and femoral shaft (28.8%). Tenofovir-induced osteomalacia is encountered in individuals on prolonged treatment with tenofovir. Treatment consists of changing to a non-tenofovir-based regimen, as well as supplementation of phosphate and calcitriol. Treatment results in remarkable improvement in symptoms and most densitometric indices. Learning points: Tenofovir is a nucleotide reverse transcriptase inhibitor (NRTI) and is a major drug in the treatment of retroviral and hepatitis B infections. Tenofovir-related hypophosphatemic osteomalacia is related to proximal tubulopathy and is not an uncommon occurrence. Treatment mandates changing to a non-tenofovir-based regimen with supplementation of neutral phosphate and calcitriol. Treatment results in a significant improvement in bone mineral density, trabecular bone score and hip geometric parameters.

The Indian Society for Bone and Mineral Research (ISBMR) position statement for the diagnosis and treatment of osteoporosis in adults.

The Indian Society for Bone and Mineral Research (ISBMR) has herein drafted clinical practice guidelines for the diagnosis and management of osteoporosis for the people of India. Implementation of the position statement in clinical practice is expected to improve the overall care of patients with osteoporosis in India. PURPOSE: In India, osteoporosis is a major public health problem. However, in the absence of any robust regional guidelines, the screening, treatment, and follow-up of patients with osteoporosis are lagging behind in the country. METHODS: The Indian Society for Bone and Mineral Research (ISBMR), which is a multidisciplinary group of physicians, researchers, dietitians, and epidemiologists and who study bone and related tissues, in their annual meeting, drafted the guidelines for the diagnosis and management of osteoporosis that would be appropriate in a resource constraint setting like India. RESULTS: Diagnosis of osteoporosis can be made in a patient with minimal trauma fracture without the aid of any other diagnostic tools. In others, bone mineral density measured by dual-energy X-ray absorptiometry remains the modality of choice. Data indicates that osteoporotic fractures occur at an earlier age in Indians than in the West; hence, screening for osteoporosis should begin at an earlier age. FRAX can be used for fracture risk estimation; however, it may underestimate the risk of future fractures in our population and still needs validation. Maintaining optimum serum 25-hydroxyvitamin D levels is essential, which, in most cases, would require regular vitamin D supplementation. Pharmacotherapy should be guided by the presence/absence of vertebral/hip fractures or the severity of risk based on clinical factors, although bisphosphonates remain the first choice in most cases. Regular follow-up is essential to ensure adherence and response to therapy. CONCLUSIONS: Implementation of the position statement in clinical practice is expected to improve the overall care of patients with osteoporosis in India.

Knowledge gap regarding osteoporosis among medical professionals in Southern India.

RATIONALE, AIMS, AND OBJECTIVES: Osteoporosis is a common health problem in India, which leads to significant morbidity and mortality in elderly individuals. Lack of knowledge and awareness among medical professionals is one of the important barriers in management of these patients. Therefore, this study was conducted to assess knowledge pertaining to diagnosis and treatment of osteoporosis among a group of Indian medical practitioners. METHODS: The study participants included 222 allopathic medical professionals, either graduate or postgraduate working in primary or secondary health care levels. They were assessed using a previously validated Fogelman's multiple choice questionnaire. Out of a total of 18 questions, four questions pertained to knowledge of diagnosis, three questions to treatment decisions, one question to assess knowledge regarding recommended dosage of vitamin D and calcium supplementation, five questions concerned medication use, and the rest to assess attitude and practices. The correct answers were converted into scores and expressed as percentages with a maximum of 100. RESULTS: The mean total score among them was 22.5%, which was quite low. Almost all of them had a score of less than 50%. Medical practitioners performed better in diagnosis-related questions, (19.4% answered all options correctly) than in medication knowledge (no correct response regarding side effects and 2% regarding contraindications). In treatment-related decisions, 37.4% answered correctly for duration of treatment, and 59% answered correctly for treatment goal. Only 1.4% of them were able to answer correctly regarding recommended calcium and vitamin D intake. Professional literature, conferences, and Continuing Medical Education (CME's) were regarded as the main sources of information on the subject by 40% of practitioners. CONCLUSION: This study showed suboptimal knowledge among a group of medical professionals regarding various aspects of diagnosis and management of osteoporosis, and it stipulates the need for escalating the efforts to improve their knowledge regarding various aspects of osteoporosis.

The Role of Magnesium in Post-thyroidectomy Hypocalcemia.

BACKGROUND: The purpose of this study was to determine the prevalence of hypomagnesemia in patients undergoing thyroidectomy and evaluate the relationship of hypomagnesemia with transient and severe hypocalcemia. MATERIALS AND METHODS: This was a prospective observational study of 50 patients undergoing thyroidectomy. Blood samples were collected pre- and postoperatively for calcium, albumin, magnesium, phosphorous and parathormone (PTH). Signs, symptoms of hypocalcemia and volume of intravenous fluids used perioperatively were documented. The statistical analysis was performed using STATA I/C 10.1. RESULTS: Preoperatively, twelve patients (24 %) had hypomagnesemia and one (2 %) hypocalcemia. On the first postoperative day, hypomagnesemia was seen in 70 % and hypocalcemia in 30 %. A similar trend was observed in the fall and rise of postoperative calcium and magnesium values (p = 0.41). Severe hypocalcemia was present in three patients (6 %). All three patients had a very low postoperative PTH (<2 pg/ml). Among them, two patients (66 %) had hypomagnesemia and their hypocalcemia responded to intravenous magnesium correction. Significant risk factors for postoperative hypocalcemia include a higher volume of fluid used perioperatively and low postoperative PTH (<8 pg/ml) (p = 0.01 and 0.03, respectively). CONCLUSION: Preoperative hypomagnesemia (24 %) was prevalent in this cohort of patients. Postoperative hypomagnesemia is a common event (70 %) following total thyroidectomy, and magnesium levels tend to mimic the calcium levels postoperatively. The cause of hypocalcemia post-thyroidectomy in this study is mainly a factor of parathyroid function and fluid status. Severe hypocalcemia is a rare event, and hypomagnesemia is associated in the majority of these patients. The role of magnesium correction to alleviate severe hypocalcemia needs to be further studied.

Dietary calcium intake and physical activity levels among urban South Indian postmenopausal women.

INTRODUCTION: Calcium is the most abundant mineral in our body with varied functions and its dietary deficiency leads to osteoporosis, besides playing a significant role in the pathogenesis of other diseases. The data regarding dietary calcium intake (DCI) among postmenopausal women in urban areas of South India is limited. OBJECTIVES: This study was aimed to assess DCI and physical activity among postmenopausal women. The risk factors for a low intake of dietary calcium were also assessed. MATERIALS AND METHODS: A cross-sectional study was done among 106 postmenopausal women selected by systematic random sampling from the city of Erode, Tamil Nadu, India. DCI and physical activity were measured using validated questionnaires. RESULTS: The mean DCI was 632.72 ± 28.23 mg/day. The proportion of women consuming less than 800 mg/day of dietary calcium was 74.5%. Only 10.4% of the women studied (11 out of 106) were on calcium supplements while 55% had low physical activity. A low knowledge score [adjusted odds ratio (OR): 5.17; 95% confidence interval (CI): 1.31-20.42] and a low socioeconomic status (SES) score of the family (adjusted OR: 4.00; 95% CI: 1.32-12.11) were significantly associated with low DCI after adjusting the age, dietary preferences, and educational and occupational statuses. CONCLUSIONS: DCI was below the Recommended Dietary Allowance (RDA) and the majority of postmenopausal women were physically inactive, indicating the need for better education regarding DCI and the need for calcium supplements and physical activity, all of which can contribute to the prevention of the consequences of osteoporosis.

Prevalence of osteoporosis in ambulatory postmenopausal women from a semiurban region in Southern India: relationship to calcium nutrition and vitamin D status.

OBJECTIVE: To assess the prevalence of osteoporosis in healthy ambulatory postmenopausal Indian women as measured by dual-energy x-ray absorptiometry and to study the dietary calcium intake and vitamin D status and their influence on bone mineral density (BMD). METHODS: We conducted a community-based cross-sectional study in a semiurban region. A randomized cluster sampling technique was used. The study cohort consisted of 150 ambulatory postmenopausal women (> or = 50 years old). Dual-energy x-ray absorptiometry for BMD was performed at the lumbar spine and femoral neck. Dietary calcium intake and biochemical variables were assessed. RESULTS: The prevalence of osteoporosis was 48% at the lumbar spine, 16.7% at the femoral neck, and 50% at any site. The mean dietary calcium intake was much lower than the recommended intake for this age-group. There was a significant positive correlation between body mass index and BMD at the lumbar spine and the femoral neck (r = 0.4; P = .0001). BMD at the femoral neck was significantly less (mean, 0.657 versus 0.694 g/cm(2)) in the vitamin D-insufficient study subjects in comparison with the vitamin D-sufficient women (P = .03). CONCLUSION: The high prevalence of osteoporosis and vitamin D insufficiency in this semiurban group of postmenopausal women in India is a major health concern. Measures such as adequate calcium intake and vitamin D supplementation in women of this age-group may be beneficial.