Effect of vitamin D3 and calcium carbonate supplementation on muscle strength in postmenopausal women living with HIV.

BACKGROUND: Both falls and fractures are increased in older persons living with HIV (PLWH). Low serum total 25-hydroxyvitamin D (25-OHD) levels have been associated with falls, fractures and poor muscle strength. We hypothesized that vitamin D (VitD) supplementation would improve muscle strength in postmenopausal PLWH. METHODS: In a 12-month prospective, randomized, double-blind, study of 69 African American and Hispanic postmenopausal PLWH on antiretroviral therapy with 25-OHD ≥10 ng/ml and ≤32 ng/ml, we investigated the effects of daily low (1,000 IU; n=31) and moderate (3,000 IU; n=38) cholecalciferol doses on lean mass and strength. Change in lean body mass was assessed by dual-energy X-ray absorptiometry (DXA), and isometric and isokinetic muscle strength in the dominant lower extremity was assessed using the Biodex System 4 Pro. RESULTS: Mean age was 56 ±5 years, median CD4+ T-cell count 722 cells/mm3 and 74% had HIV RNA≤50 copies/ml. Serum 25-OHD did not differ at baseline, but was higher in the moderate than low VitD group at 6 and 12 months. In both groups, there were significant increases in lower extremity isokinetic torque, work and power at 12 months, with no change in lean mass. CONCLUSIONS: VitD supplementation was associated with a modest increase in lower extremity strength in postmenopausal PLWH, without a concomitant increase in muscle mass. Magnitude of increase in strength were similar with 3,000 IU and 1,000 IU daily. Future larger studies will be required to determine the optimal dose of VitD to improve muscle strength and to determine whether supplementation reduces the risk of falls and fractures in PLWH.

A Randomized Placebo-Controlled Trial of Low- Versus Moderate-Dose Vitamin D3 Supplementation on Bone Mineral Density in Postmenopausal Women With HIV.

BACKGROUND: Prevalence of osteoporosis and fracture is increased among older people with HIV. We compared the effects of low (1000 IU) vs moderate (3000 IU) vitamin D3 (VitD) supplementation on areal bone mineral density (aBMD) and volumetric bone mineral density (vBMD) in African American and Hispanic postmenopausal women with HIV on antiretroviral therapy. METHODS: We performed a 12-month prospective, randomized, double-blind, placebo-controlled study with primary outcomes of change in aBMD by dual-energy X-ray absorptiometry (DXA) and secondary outcomes of change in vBMD by quantitative computed tomography and bone turnover markers. An intent-to-treat analysis was performed on 85 randomized subjects (43 low and 42 moderate) for primary DXA outcomes, and complete case analysis was performed for secondary outcomes. RESULTS: Mean age was 56 ± 5 years, median CD4 count was 722 cells/mm, and 74% had HIV RNA ≤ 50 copies/mL. Serum 25-OHD was higher in the moderate than low VitD group at 6 months (33.1 ± 10.3 vs 27.8 ± 8.1 ng/mL, P = 0.03) and 12 months, but parathyroid hormone levels remained similar. Percent change in aBMD, vBMD, and bone turnover markers did not differ between low and moderate VitD groups before or after adjustment for baseline aBMD. CONCLUSIONS: VitD supplementation at 3000 IU daily increased mean total 25-OHD levels in postmenopausal women with HIV, but we did not find evidence of an effect on BMD beyond those observed with 1000 IU daily. Future studies are necessary to determine whether VitD supplementation is beneficial in this patient population, and if so, what dose is optimal for skeletal health.

Representation of spectro-temporal features of spoken words within the P1-N1-P2 and T-complex of the auditory evoked potentials (AEP).

The purpose of the study was to determine whether P1-N1-P2 and T-complex morphology reflect spectro-temporal features within spoken words that approximate the natural variation of a speaker and whether waveform morphology is reliable at group and individual levels, necessary for probing auditory deficits. The P1-N1-P2 and T-complex to the syllables /pət/ and /sət/ within 70 natural word productions each were examined. EEG was recorded while participants heard nonsense word pairs and performed a syllable identification task to the second word in the pairs. Single trial auditory evoked potentials (AEP) to the first words were analyzed. Results found P1-N1-P2 and T-complex to reflect spectral and temporal feature processing. Also, results identified preliminary benchmarks for single trial response variability for individual subjects for sensory processing between 50 and 600ms. P1-N1-P2 and T-complex, at least at group level, may serve as phenotypic signatures to identify deficits in spectro-temporal feature recognition and to determine area of deficit, the superior temporal plane or lateral superior temporal gyrus.