Abstract 9: Low bone mineral density, hypovitaminosis D, hypophosphatemia, increased fractional excretion of phosphorous and sarcopenia in persons living with human immunodeficiency virus (Plhiv) taking tenofovir based anti-retro viral therapyin a tertiary care center in South India

Background: After the advent of anti-retroviral therapy (ART), treatment of Human immunodeficiency virus (HIV) has made a considerable journey from a being a fatal condition to a chronic manageable disease. Metabolic bone disorders due to HIV virus and ART can lead to reduced bone mineral density, osteoporosis, hypocalcemia, hypophosphatemia, hypovitaminosis D and hypomagnesemia. Sarcopenia in PLHIV is another relevant complication. There are few studies regardingHIV and treatmentconsequences on bone. ART (Tenofovir based regimens) causing renal tubular dysfunction and hence proteinuria, bicarbonaturia, glycosuria, phosphaturia and hypophosphatemia with muscle weakness are relatively understudied. Aims and Objectives: The current study was done in a tertiary care center with a primary objective of estimation of bone mineral density in (PLHIV). The secondary objectives were to estimate prevalence and risk factors of hypocalcemia, hypophosphatemia, hypovitaminosis D and hypomagnesemia in PLHIV and to estimate prevalence and risk factors of sarcopenia in PLHIV. Materials and Methods: This is a cross sectional study wherein PLHIV aged 18-49 years were consecutively selected from the ART clinic in Medical College, Thiruvananthapuram. They were evaluated with structured proforma, clinical examination, blood and urine tests after taking informed consent. Bone mineral density and sarcopenia was assessed with DEXA (dual energy Xray absorptiometry) scan. Results: Ninety PLHIV were included in the study. There were 48 females and 42 males. Mean age was 40.7 years. 10 patients (11.1%) had symptoms suggestive of bone and muscle pain. 15 patients (16.7%) had symptoms and signs suggestive of proximal myopathy. The range of body mass index was 15 to 36 kg/m2. Mean body mass index was 23.6 ± 4.4. Bone Mineral density in Lumbar spine ranged from 0.671 to 1.416 g/cm2. Low Bone mineral density was seen in 14 participants (15.5%). Low bone mineral density had correlation with duration of illness and age of the patient. Six participants (6.7%) had hypophosphatemia. TMP -GFR (tubular maximum reabsorption of phosphate to glomerular filtration rate) was less than 2.5 in these patients. Fifteen patients (16.6%) had abnormally increasedfractional excretion of phosphate (FEP%) (>20%). Hypophosphatemia andFEP% correlates with duration of Tenofovir based Anti-retroviral therapy (p < 0.01). They also correlate with symptoms and signs of proximal myopathy (p < 0.01) and sarcopenia (p-0.031). Low serum bicarbonate was seen in 34 participants (37.7%). Vitamin D insufficiency was seen in 63 (70%) participants and 31 (34.4%) had deficiency. Eight (8.8%) participants had significant proteinuria and 12 (13.3%) had glycosuria. None of the study participants had hypocalcemia and hypomagnesemia. Sarcopenia (reduced appendicular skeletal mass/height in m2) was seen in 27 participants (30%). Significant correlation was seen with the time since disease diagnosis (p-0.017) and protein intake in grams (p-0.01). Sarcopenia also significantly correlates with symptoms and signs of proximal myopathy (p-<0.01) and FEP% (p-0.031). Conclusions: Significant proportion ofPLHIV hadlow bone mineral densityas well as sarcopenia. They require timely diagnosis and appropriate management. Hypovitaminosis D is common among PLHIV. Hypophosphatemia causing proximal myopathy was seen in 6.7% PLHIV. Increased fractional excretion of phosphorous (which can be a predictor for hypophosphatemia and future tubular dysfunction) was seen in 1/6th of the study participants. Other investigations suggesting renal tubular dysfunction were low bicarbonate levels, proteinuria and glycosuria. Regular monitoring of serum calcium, phosphorous, vitamin D, fractional excretion of phosphorous, urine protein creatinine ratio, glycosuria and DEXA scan with body composition analysis may be considered in the HIV treatment guidelines.