Homocysteïne, foliumzuur en botontkalking.*

Uit een Noorse studie onder ruim 5.000 mensen van 47 tot 75 jaar blijkt dat er bij vrouwen een duidelijk verband is tussen de bloedwaarden homocysteïne, foliumzuur en botdichtheid. Lage botdichtheid zoals bij osteoporose is gerelateerd aan lage waarden foliumzuur en omgekeerd evenredig met de hoeveelheid homocysteïne. Vrouwen met lage botdichtheid en daardoor een grotere kans op osteoporose hadden doorgaans hoge homocysteïne en lage foliumzuur waarden.

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Plasma Total Homocysteine Level and Bone Mineral Density

The Hordaland Homocysteine Study

Clara Gram Gjesdal, MD; Stein Emil Vollset, MD, DrPH; Per Magne Ueland, MD, PhD; Helga Refsum, MD, PhD; Christian A. Drevon, MD, PhD; Håkon K. Gjessing, PhD; Grethe S. Tell, PhD

Arch Intern Med. 2006;166:88-94.

Background  Plasma total homocysteine (tHcy) has been associated with hip fracture but not directly with bone mineral density (BMD). We examined the association of hip BMD with levels of plasma tHcy, folate, and vitamin B₁₂ and the methylenetetrahydrofolate reductase (MTHFR) 677C7" T and 1298AC polymorphisms.

Methods  Bone mineral density was measured between 1997 and 2000 in 2268 men and 3070 women, aged 47 to 50 and 71 to 75 years, from the Hordaland Homocysteine Study cohort. Low BMD was defined as BMD in the lowest quintile for each sex and age group. Linear, logistic, and generalized additive regression models were used.

Results  Plasma levels of tHcy were inversely related to BMD among middle-aged and elderly women (P<.001) but not among men. The multiple adjusted odds ratio for low BMD among subjects with high (15 µmol/L [2.02 mg/L]) compared with low (<9 µmol/L [<1.22 mg/L]) tHcy level was 1.96 (95% confidence interval, 1.40-2.75) for women and was not significant for men. Additional adjustments for plasma folate level or intake of calcium and vitamin D did not substantially alter the results. Plasma folate level was associated with BMD in women only. We observed no association between BMD and vitamin B₁₂ level or the MTHFR polymorphisms.

Conclusions  Elevated tHcy and low folate levels were associated with reduced BMD in women but not in men. These findings suggest that tHcy may be a potential modifiable risk factor for osteoporosis in women. (Februari 2006)