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Low plasma 25-hydroxyvitamin D [25(OH)D] levels are associated with high cardiovascular risk. This may be because that low 25(OH)D levels are associated with high levels of atherogenic lipoproteins, but whether these 2 risk factors are genetically associated is unknown. We tested this hypothesis.Using a Mendelian randomization approach, potential genetic associations between plasma levels of atherogenic lipoproteins and 25(OH)D were examined in 85 868 white, Danish individuals in whom we genotyped for variants affecting plasma levels of 25(OH)D, nonfasting remnant cholesterol, low-density lipoprotein-cholesterol, and high-density lipoprotein-cholesterol. Lipoprotein levels were measured in all and 25(OH)D levels in 31 435. A doubling in nonfasting remnant cholesterol levels was observationally and genetically associated with -6.0%(95% confidence interval [CI], -6.5% to -5.5%) and -8.9% (95% CI, -15% to -2.3%) lower plasma 25(OH)D levels. For low-density lipoprotein-cholesterol levels, corresponding values were -4.6% (95% CI, -5.4% to -3.7%) observationally and -11% (95% CI, -29% to +6.9%) genetically. In contrast, a halving in high-density lipoprotein-cholesterol levels was observationally associated with -1.5% (95% CI, -2.2% to -0.7%) lower but genetically associated with +20% (95% CI, +7.4% to +34%) higher plasma 25(OH)D levels. Plasma levels of lipoprotein(a) and 25(OH)D did not associate. Finally, low 25(OH)D levels did not associate genetically with levels of remnant and low-density lipoprotein-cholesterol.Genetically elevated nonfasting remnant cholesterol is associated with low 25(OH)D levels, whereas genetically reduced high-density lipoprotein-cholesterol is not associated with low 25(OH)D levels. These findings suggest that low 25(OH)D levels observationally is simply a marker for elevated atherogenic lipoproteins and question a role for vitamin D supplementation in the prevention of cardiovascular disease. [ABSTRACT FROM AUTHOR]

Pseudoxanthoma elasticum (PXE) is an autosomal recessive disease caused by loss-of-function mutations in ABCC6 and characterized by elastic calcification leading to dermal, ocular, and ischemic vascular disease. We tested the hypothesis that heterozygosity for R1141X, the most frequent PXE-causing mutation in Caucasians, associated with risk of ischemic vascular disease, as previous studies suggested 4- to 11-fold risk of ischemic heart disease (IHD) in heterozygotes.We studied 10 276 persons from the general population, including 1985 with IHD and 989 with ischemic cerebrovascular disease (ICVD). We examined 45 603 individuals from a cross-sectional general population study, of whom 3738 had IHD and 2335 had ICVD. Finally, we compared 4851 patients with IHD and 625 patients with ICVD with, respectively, 4851 and 625 matched control subjects. We genotyped participants in all studies for ABCC6 R1141X. The frequency of R1141X was 0.6% in all populations studied. ABCC6 R1141X genotype was not associated with an increased risk of IHD, myocardial infarction, ICVD, or ischemic stroke. Furthermore, R1141X genotype did not interact with age on risk of the largest end point, IHD. Finally, R1141X genotype did not associate with variation in plasma levels of high-sensitivity C-reactive protein, fibrinogen, blood pressure, or lipid and lipoproteins in the general population.In 4 studies including 66 831 participants and 13 642 cases with ischemic vascular events, heterozygosity for ABCC6 R1141X did not associate with risk of IHD, myocardial infarction, ICVD, or ischemic stroke. [ABSTRACT FROM AUTHOR]