Evaluation of serum 25-hydroxyvitamin D levels in calcific rheumatic mitral stenosis- A cross sectional study

1,25-dihydroxyvitamin D deficiency is independently associated with cardiac valve calcification in patients with chronic kidney disease

Cardiac valve calcification is highly prevalent in patients with chronic kidney disease (CKD). Low vitamin D levels are associated with vascular calcification in CKD. However, the association between vitamin D levels and cardiac valve calcification is unknown. A total of 513 patients with pre-dialysis CKD were included in this cross-sectional study. Aortic valve calcification (AVC) and mitral valve calcification (MVC) were assessed using two-dimensional echocardiography. The associations between AVC and MVC and baseline variables were investigated using logistic regression analyses. In multivariable analysis, serum 1,25(OH)₂D level was independently associated with AVC (odds ratio [OR], 0.87; P < 0.001) and MVC (OR, 0.92; P < 0.001). Additionally, age, diabetes, coronary heart disease, calcium × phosphate product, and intact parathyroid hormone levels were independently associated with AVC and MVC. Systolic blood pressure was independently associated with AVC. A receiver-operating characteristic (ROC) curve analysis showed that the best cutoff values of serum 1,25(OH)₂D levels for predicting AVC and MVC were ≤ 12.5 and ≤ 11.9 pg/dl, respectively. Serum 1,25(OH)₂D deficiency is independently associated with AVC and MVC in patients with CKD, suggesting that serum 1,25(OH)₂D level may be a potential biomarker of AVC and MVC in these patients.

Evaluating Vitamin D levels in Rheumatic Heart Disease patients and matched controls: A case-control study from Nepal

Background

Diagnosis and treatment for Rheumatic Heart Disease (RHD) is inaccessible for many of the 33 million people in low and middle income countries living with this disease. More knowledge about risk factors and pathophysiologic mechanisms involved is needed in order to prevent disease and optimize treatment. This study investigated risk factors in a Nepalese population, with a special focus on Vitamin D deficiency because of its immunomodulatory effects.

Methods

Ninety-nine patients with confirmed RHD diagnosis and 97 matched, cardiac-healthy controls selected by echocardiography were recruited from hospitals in the Central and Western region of Nepal. Serum 25(OH)D concentrations were assessed using dried blood spots and anthropometric values measured to evaluate nutritional status. Conditional logistic regression analysis was used to define association between vitamin D deficiency and RHD.

Results

The mean age of RHD patients was 31 years (range 9–70) and for healthy controls 32 years (range 9–65), with a 4:1 female to male ratio. Vitamin D levels were lower than expected in both RDH and controls. RHD patients had lower vitamin D levels than controls with a mean s-25(OH)D concentration of 39 nmol/l (range 8.7–89.4) compared with controls 45 nmol/l (range 14.5–86.7) (p-value = 0.02). People with Vitamin D insufficiency had a higher risk (OR = 2.59; 95% CI: 1.04–6.50) of also having RHD compared to people with Vitamin D concentrations >50 nmol/l. Body mass index was significantly lower in RHD patients (22.6; 95% CI, 21.5–23.2) compared to controls (24.2; 95% CI, 23.3–25.1).

Conclusion

RHD patients in Nepal have lower Vitamin D levels and overall poor nutritional status compared to the non-RHD controls. Longitudinal studies are needed to explore the causality between RHD and vitamin D level. Future research is also recommended among Nepali general population to confirm the low level of vitamin D as reported in our control group.