The association between serum folate and elderly diastolic hypertension: results from the NHANES (2007-2018).

Aim: To explore the association between serum folate concentration and the prevalence of elderly diastolic hypertension. This study aims to identify potential relationships that could inform further research into the mechanisms underlying hypertension management.

Methods: Data from six NHANES cycles (2007-2008, 2009-2010, 2011-2012, 2013-2014, 2015-2016, and 2017-2018) were analysed for individuals aged over 60. Weighted logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup and restricted cubic spline (RCS) regression explored the serum folate concentration and elderly diastolic hypertension relationship.

Results: This study included 9,419 participants (4,734 females and 4,685 males) with a mean age of 70.0 ± 7.0 years. Among them, 360 were diagnosed with diastolic hypertension. In the fully adjusted model, there was a negative correlation between serum folate concentration and the prevalence of diastolic hypertension (OR 0.65; 95% CI: 0.52-0.82). When serum folate concentration levels were divided into quartiles (in μg/dL), the ORs for diastolic hypertension corresponding to Q2 (1.29-1.98), Q3 (1.99-3.08), and Q4 (3.09-5.56) levels compared to Q1 (0.18-1.28) were 1.41 (95% CI: 0.60-3.33), 0.48(95% CI: 0.20-1.16), and 0.35 (95% CI: 0.16-0.74), respectively, with a P for trend <.05. Restricted cubic spline plots showed a negative correlation between serum folate concentration and the prevalence of diastolic hypertension (non-linearity: p = .495). Subgroup analysis indicated that the negative correlation between serum folate concentration and the prevalence of diastolic hypertension was more significant in female participants (interaction p = .009).

Conclusion: Higher serum folate concentration is associated with a lower prevalence of diastolic hypertension in the elderly.