Association of vitamin D deficiency with electrocardiographic markers of left atrial abnormalities

A randomized clinical trial of omega-3 fatty acid and vitamin D supplementation on electrocardiographic risk profiles

Beneficial and adverse associations with arrhythmias have been reported for omega-3 fatty acids (omega-3 FA) and Vitamin D. The 12 lead electrocardiogram (ECG) contains quantitative measures reflecting diverse aspects of electrophysiology that might provide insights into mechanisms underlying these associations. In a pre-specified ancillary study of the VITaminD and omegA-3 (VITAL) trial, we examined the effect of 1 g of marine omega-3 FA per day, comprised of 460 mg eicosapentanoic acid and 380 mg of docosahexaenoic acid, and 2000 IU VitaminD3 per day on ECG characteristics associated with atrial and ventricular arrhythmias among individuals age 50 years or greater. A total of 911 study participants underwent ECGs at baseline and again at 2 years after the randomization. Individuals randomized to active omega-3 FA demonstrated significant net increase in PR-interval duration (p = 0.005) and P-wave duration (p = 0.03) as well significant net decrease in P-wave amplitude (p = 0.037) as compared to placebo. RMSSD increased to a greater extent in the omega-3 FA arm compared to placebo (p = 0.040). For Vitamin D3, the Cornell voltage increased to a lesser extent in the participants assigned to active treatment as compared to placebo (p = 0.044). There were no other significant differences in QRS, QTc, Cornell voltage or heart rate. Thus, randomized treatment with omega-3 FA supplements resulted in changes on the ECG that are potentially reflective of heightened vagal tone and/or slowing of intraatrial and AV conduction. Vitamin D3 supplementation resulted in modest reductions in progressive LV voltage suggestive of a potential antihypertrophic effect.Trial registration ClinicalTrials.gov Identifiers: NCT01169259, NCT02178410 (06/26/2010 and 06/30/2014).

The relationship between famine exposure in early life and left atrial enlargement in adulthood

BACKGROUND

Increased left atrium diameter (LAD) is associated with an elevated risk of cardiovascular diseases. The relationship between nutrition status and left atrial enlargement (LAE) is still unclear. The present study aimed to investigate the association of famine exposure in early life with LAE in adulthood.

METHODS

Participants were divided into non-exposed, fetal, early, middle and late childhood exposed groups according to birth data. LAE was defined when LAD was ≥3.9 cm in women and ≥4.1 cm in men, or ≥2.3 cm m^-2 by a sex-independent cut-off normalised for body surface area. Multivariate logistic regression was performed to calculate the odds ratio (OR) and confidence interval (CI) between famine exposure and LAE.

RESULTS

In total, 2522 [905 male, mean (SD) age 59.1 (3.65) years] subjects were enrolled, including 392 (15.5%) LAE subjects. The prevalence of LAE in non-exposed, fetal, early, middle and late childhood exposed groups was 55 (10.8%), 38 (11.2%), 88 (18.1%), 102 (16.7%) and 109 (19.0%), respectively. Compared to the non-exposed group, the ORs for LAE were in fetal (OR = 0.956, 95% CI = 0.605-1.500, P = 0.847), late (OR = 1.748, 95% CI = 1.208-2.555, P = 0.003), middle (OR = 1.647, 95% CI = 1.140-2.403, P = 0.008) and early (OR = 1.630, 95% CI = 1.116-2.399, P = 0.012) childhood exposed groups after adjusting potential cofounders. When stratified by gender, smoking, body mass index, hypertension and diabetes, we found that the effect of famine exposure on LAE was only modified by diabetes (P_interaction  = 0.007).

CONCLUSIONS

Famine exposure during childhood stage might increase the risk of LAE in adults, and this effect interacts with diabetes.

Association of vitamin D deficiency with electrocardiographic markers of left atrial abnormalities

OBJECTIVE

Electrocardiographic markers of left atrial (LA) abnormalities are linked to increased risk of cardiovascular disease (CVD). We examined the relationship of vitamin D deficiency with prolonged P wave duration and PR interval as markers of LA abnormalities.

METHODS

This analysis included 5,894 participants (58.12 ± 12.9 years; 54.7% women; 49.8% non-Hispanic Whites) without clinical CVD from NHANES III. A multivariable logistic regression model was used to examine the association of vitamin D categories (<20 ng/ml, 20-29 ng/ml and >30 ng/ml (reference) with prolonged P wave duration (≥120 ms) and PR interval (≥200 ms).

RESULTS

There was an incremental increase in the prevalence of prolonged P wave duration and PR interval across vitamin D categories with the highest prevalence in study participants with vitamin D levels <20 ng/ml, followed by 20-29 ng/ml and then >30 ng/ml (trend p-value < 0.0001). Vitamin D deficiency (<20 ng/ml) was associated with prolonged P wave duration (OR [95% CI]: 1.22 [1.03-1.45], p = 0.02) and prolonged PR interval (OR [95% CI]: 1.48 [1.12-1.97], p = 0.006) in multivariable logistic regression models adjusted for demographics, CVD risk factors, and other potential confounders. These associations were consistent across subgroups stratified by age, sex, and race.

CONCLUSIONS

Vitamin D deficiency is associated with an increased risk of LA abnormalities. This association elucidates an alternate pathway through which vitamin D deficiency may increase CVD risk. Whether vitamin D supplementation would improve LA abnormalities requires further investigation.