Large artery stiffness and carotid intima-media thickness in relation to markers of calcium and bone mineral metabolism in African women older than 46 years

Abstract

Vascular calcification and cardiovascular diseases have been associated with altered bone metabolism. We explored the relationships of arterial pressures and carotid intima-media thickness (CIMT) with parathyroid hormone, 25-hydroxycholecalciferol and their ratio (PTH:25(OH)D3) as well as a marker of bone resorption (CTX) in lean and overweight/obese African women. A population of 434 African women older than 46 years was divided into lean and overweight/obese groups. We assessed brachial blood pressure, central pulse pressure (cPP) and CIMT, and determined PTH, 25(OH)D3 and CTX concentrations. Overweight/obese women had elevated PTH and PTH:25(OH)D3 compared with lean women (both P<0.001), whereas lean women had higher CTX (P<0.001). Single, partial and multiple regression analyses indicated that, in lean women CIMT was independently associated with PTH:25(OH)D3 (R(2)=0.22; β=0.26; P=0.003), whereas in obese women cPP was associated with both PTH:25(OH)D3 (R2=0.20; β=0.17; P=0.017) and CTX (R2=0.20; β=0.17; P=0.025). In conclusion, we found that in African women with increased adiposity, cPP (as a surrogate measure of arterial stiffness), was positively associated with alterations in bone metabolism and calciotropic hormones, whereas CIMT of lean women was positively associated with PTH:25(OH)D3. Our results suggest that alterations in bone and calcium metabolism may contribute to arterial calcification in older African women.

CRP Genotypes Predict Increased Risk to Co-Present with Low Vitamin D and Elevated CRP in a Group of Healthy Black South African Women

“…Li [ 50 ] hypothesized that vitamin D could have an influence on the renin–angiotensin system (RAS), which was substantiated by a study that reported how low concentrations of 25(OH)D upregulated the RAS [ 51 ]. In our population, 25(OH)D was reported to be associated with carotid wall thickening and arterial stiffness [ 52 ], both being attributes observed in individuals with increased CRP concentrations. This is a possible mechanism whereby low 25(OH)D could result in increased arterial stiffness, and in turn result in increased blood pressure [ 53 ], leading to elevated CRP concentration by negative feedback mechanisms.…”

Reply to: systematic review and meta‐analysis for the association of bone mineral density and osteoporosis/osteopenia with vascular calcification in women

“…The authors conclude that patients with vascular calcification "have lower lumbar spine and hip BMD and increased risk for developing osteoporosis or osteopenia". Whilst it is possible that aspects of increased vascular calcification may contribute to declines in bone density (through common risk factors such as age, smoking, low levels of physical activity and chronic inflammation), this conclusion potentially ignores evidence that vascular calcification can also result from dysregulated bone metabolism in ageing [2][3][4].…”