The Association between Vitamin D Hypovitaminosis and Cardiovascular Disease Risk in Saudi Diabetic Patients Type II

Association of serum vitamin D and the risk of cardiovascular diseases among diabetic patients: A systematic review and meta-analysis

BACKGROUND

The emerging role of vitamin D has drawn the attention of researchers around the world, including its involvement in cardiovascular complications among individuals with diabetes.

AIM

This study aimed to obtain comprehensive evidence on the association between serum vitamin D level and the risk of cardiovascular disease among patients with diabetes.

METHODS

Systematic search was performed on July 1st, 2023, to identify and screen published literature reporting the association between vitamin D and cardiovascular disease among diabetic patients in six databases. Each eligible study was appraised for its quality using modified Newcastle Ottawa Scale for cross-sectional and cohort studies. Meta-analysis was performed using Dersimonian-Laird random effect model or fix-effect model. The heterogeneity and publication bias were judged based on percentage of I2 and the symmetry of Begg's funnel plot, respectively.

RESULTS

As many as 22 studies were found eligible for the systematic review. A meta-analysis from 13 studies comprising of 3850 and 1797 (control and exposure groups, respectively) revealed that serum vitamin D level was significantly lower in patients with diabetes and cardiovascular diseases (Z = 4.89; p-total<0.001; SMD = 0.68 [95%CI: 0.41-0.95]), yet the heterogeneity was high. Following the adjustment of removing the potential outliers, the same results were still observed (Z = 6.19; p-total<0.001; SMD = 0.35 [95%CI: 0.24-0.46]). Though decreased, high heterogeneity could not be resolved, resulting in moderate level of this evidence. Another pooled analysis of 7 studies with 4211 patients in control group and 2381 patients in exposure group revealed that lower level of serum vitamin D is a risk factor for cardiovascular disease incidence among diabetic patients (Z = 4.89; p-total<0.001; OR: 1.76 [95%CI: 1.4-2.2]).

CONCLUSION

Serum vitamin D level status is a risk factor for developing cardiovascular diseases among diabetic patients, hence should be carefully monitored and maintained.

PROSPERO REGISTRATION

CRD42023437698.

Novel Insight Into the Relationship of Vitamin D Hydroxylase and Vitamin D With Obesity in Patients With Type 2 Diabetes Mellitus

BACKGROUND

In patients with type 2 diabetes mellitus (T2DM) and obesity, there is often a vitamin D deficiency, which is crucial for many physiological processes. The enzyme 25-D hydroxylase activates vitamin D, and its status has been linked to glucose and lipid metabolism in these patients. This study investigates the correlation between the levels of 25-D hydroxylase and 25-hydroxyvitamin D, and their impact on glucose and lipid metabolism in Saudi patients with T2DM and obesity.

METHODS

This study involved 150 Saudi participants (ages 35-70) of both genders from King Faisal Medical Complex in Taif. The participants were divided into control, type 2 diabetic, and obese diabetic patient groups, with 50 subjects in each group. Serum levels of 25(OH) vitamin D and 25-D hydroxylase were measured using ELISA. In contrast, an automatic analyzer for chemistry tests was used to measure fasting blood glucose (FBG), aspartate transaminase (AST), alanine transaminase (ALT), and lipid profile levels. Hemoglobin A1c (HbA1c)% was analyzed using the automatic glycosylated hemoglobin analyzer. In addition, the body mass index (BMI) value was calculated using the equation (BMI = weight in kilograms/height in meters squared).

RESULTS

In obese with T2DM and T2DM patient groups, there were significant increases (p < 0.0001) in BMI, FBG, HbA1c%, total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), AST, and ALT levels and significant decreases (p < 0.0001) in 25(OH) vitamin D, 25-D hydroxylase, and high-density lipoprotein cholesterol (HDL-C) levels compared to the control group. There were significant positive correlations between vitamin D with 25-D hydroxylase and HDL-C and negative correlations with HbA1c%, FBG, TC, TG, LDL-C, ALT, AST, and BMI in the studied patient groups.

CONCLUSIONS

This study shows that lower levels of the enzyme 25-D hydroxylase are linked to reduced vitamin D levels in people with T2DM and obese diabetic patients. Additionally, there was a notable correlation between vitamin D levels and BMI, lipid profile, FBG, HbA1c%, AST, and ALT levels.

Role of Vitamins in Cardiovascular Health: Know Your Facts - Part 1

Cardiovascular (CV) disease (CVD) is a major cause of morbidity and mortality world-wide, thus it is important to adopt preventive interventions. Observational data demonstrating CV benefits of vitamin supplements, advanced by self-proclaimed experts have resulted in ~50% of Americans reporting the use of multivitamins for health promotion; this practice has led to a multi-billion-dollar business of the multivitamin-industry. However, the data on the extensive use of multivitamins show no consistent benefit for CVD prevention or all-cause mortality, while the use of certain vitamins might prove harmful. Thus, the focus of this two-part review is on the attributes or concerns about specific vitamins on CVD. In Part 1, the CV effects of specific vitamins are discussed, indicating the need for further supportive evidence of potential benefits. Vitamin A preserves CV homeostasis as it participates in many biologic functions, including atherosclerosis. However, supplementation could potentially be harmful. Betacarotene, a pro-vitamin A, conveys pro-oxidant actions that may mitigate any other benefits. Folic acid alone and certain B-vitamins (e.g., B1/B2/B6/B12) may reduce CVD, heart failure, and/or stroke, while niacin might increase mortality. Vitamin C has antioxidant and cardioprotective effects. Vitamin D may confer CV protection, but all the data are not in agreement. Combined vitamin E and C have antiatherogenic effects but clinical evidence is inconsistent. Vitamin K seems neutral. Thus, there are individual vitamin actions with favorable CV impact (certain B-vitamins and vitamins C and D), but other vitamins (β-carotene, niacin) may potentially have deleterious effects, which also holds true for high doses of fat-soluble vitamins (A/D/E/K).