Bone problems raised in several UK studies
Simon Collins, HIV i-Base
Several small studies looked at markers of bone metabolism in patients on HAART.
M Rosenvinge and colleagues from St Georges reported an unexpectedly high rate of vitamin D deficiency in a retrospective case note review of 132 consecutive patients attending their out-patients clinic from November 2007. 
They reported 58% patients (76/132) had 25-hydroxycholecalciferol (25(OH)D) deficiency including 8% (11 patients) who were severely deficient (<25nmol/L). A further 27% had borderline deficiency (50-75nmol/L) and only 16% of patients had optimum levels.
Multivariate analysis identified associations with black race (OR 0.14 95%CI 0.02-0.88, white vs black), younger age (OR 0.87, 95%CI 0.78-0.97, for every increase in age by one year) and higher random blood glucose (OR 3.21 95%CI 1.32-7.8 for every increase by 1mmol/L).
No association was found with diagnosis date, CDC stage, use/duration of tenofovir/HAART, weight, kidney/bone profile or parathyroid hormone levels.
Klassen and colleagues from Imperial College reported a case study of severe vitamin D deficiency in a 67 year old Somalian patient who had presented with bone pain, hypophosphatemia (0.64 mmol/L) and raised alkaline phosphatase (>500U/L) while on tenofovir-based HAART. 
Vitamin D levels were severely deficient (<15 nmol/L) and she had secondary hyperparathyroidism. Pelvic x-ray was normal.
Vitamin D supplement (dosed 15µg/day) rapidly improved clinical symptoms and normalised phosphate and alkaline phosphatase levels, and Truvada/efavirenz was maintained.
A second poster from this group looked at risk factors for low vitamin D in a group of 79 patients who had been assessed for 25(OH)D levels over a 2-year period. 
Mean age of the group was 41 (range 17-72), 70% were on HAART, median CD4 was 380 (range 0-930. 53% were women, 49% were African (33% Caucasian),
Median vitamin D levels were 31 nmol/L (range <15-145). 23% patients had severe deficiency (<25 nmol/L) and 70% has less than optimum levels (25-74 nmol/L). Higher levels were associated with Caucasian origin (P=0.025), current use of HAART (p=0.010) and duration of HAART (p=0.026). CD4 count, season, gender, PI or tenofovir use had no significant association (p>0.064 for all).
S Hill and colleagues from St Mary’s and Hillingdon Hospitals presented an analysis of markers of bone metabolism and the clinical impact in a retrospective review of 205 patients (45% women, 55% black) seen in their cohort during 2007. 
From a mean of almost four calcium tests during the year, 42% patients had >1 low calcium level, 23% had >1 low phosphate and 20% had >1 high phosphate.
Low calcium and phosphate levels were more common in patients on HAART and were seen in 47% vs 32% (p=0.06), and 30% vs 5% (p<0.0001) patients, but were not related to tenofovir use. Low vitamin D levels were more common in women than men (8% vs 2%), all of whom were non-Caucasian.
All references are to the Programme and Abstracts of the 14th Annual BHIVA Conference, Dublin, 2008, published as Supplement to HIV Medicine, Volume 9.
- Rosenvinge MM et al. Unexpectedly high rates of vitamin D deficiency in an inner-city London HIV clinic. Oral abstract O15.
- Klassen K et al. Vitamin D deficiency presenting with hypophosphatemia, bone pain and a raised alkaline phosphatase in a patient on tenofovir. Poster P83.
- Klassen K et al. Risk factors for hypovitaminosis D in HIV-positive individuals. Poster P95A.
- Hill S et al. How common are abnormalities of serum calcium, phosphate and vitamin D in an HIV-positive cohort and what is their clinical significance. Poster 96.