Hypovitaminosis D and orthostatic hypotension: a systematic review and meta-analysis.

OBJECTIVES: Orthostatic hypotension is a common condition among older adults and is associated with a range of deleterious outcomes. Recently, interest has developed in hypovitaminosis D (defined as low 25 hydroxiyvitamin D levels) as a potential risk factor for orthostatic hypotension. We conducted a systematic review and meta-analysis examining the association of orthostatic hypotension between study participants with and without hypovitaminosis D, including the adjustment of potential confounders (age, sex, BMI, renal function, comorbidities, seasonality, use of antihypertensive medications, and supplementation with cholecalciferol). METHODS: A systematic literature search of major electronic databases from inception until 09/2015 was made for articles providing data on orthostatic hypotension and hypovitaminosis D. A random effects meta-analysis of cross-sectional studies investigating orthostatic hypotension prevalence comparing participants with vs. those without hypovitaminosis D was undertaken, calculating the odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Of 317 initial hits, five cross-sectional studies were meta-analysed including 3646 participants (1270 with hypovitaminosis D and 2376 without). The participants with hypovitaminosis D had a higher prevalence of orthostatic hypotension (OR = 1.88; 95% CI: 1.25-2.84; I = 68%) that was not affected by adjusting for a median of five potential confounders (OR = 2.03; 95% CI: 1.13-3.68; I = 73%). People with orthostatic hypotension had significantly reduced serum vitamin D concentrations (standardized mean difference = -0.42; 95% CI: -0.72 to -0.12). One longitudinal study confirmed the association between hypovitaminosis D and orthostatic hypotension. CONCLUSION: Our meta-analysis highlights that hypovitaminosis D is associated with orthostatic hypotension, independent of potential confounders. Further longitudinal studies and clinical trials are required to confirm these findings.

Serum long-chain omega-3 polyunsaturated fatty acids and risk of orthostatic hypotension.

Long-chain omega-3 polyunsaturated fatty acids (PUFAs) from fish have been shown to lower blood pressure. However, there is little information about the association with orthostatic hypotension, for which hypertension is a risk factor. We investigated the associations between serum long-chain omega-3 PUFAs and orthostatic hypotension in 1666 middle-aged or older men and women free of cardiovascular disease (CVD), diabetes or hypertension in 1998-2001 in the Kuopio Ischemic Heart Disease Risk Factor Study (KIHD) in eastern Finland. We also investigated the associations with mercury exposure, a major source of which is fish, and which has been associated with higher CVD risk in KIHD. Orthostatic hypotension was defined as decrease in systolic blood pressure of at least 20 mm Hg or diastolic blood pressure of at least 10 mm Hg within 1 min of standing. Orthostatic hypotension was found in 146 participants (8.8%). The mean serum concentrations were 1.67% (s.d. 0.92) for eicosapentaenoic acid, 0.79% (s.d. 0.16) for docosapentaenoic acid (DPA) and 2.78 (s.d. 0.92) for docosahexaenoic acid of all serum fatty acids. The mean pubic hair mercury concentration was 1.5 µg g(-1) (s.d. 1.6). We did not find statistically significant associations between the serum long-chain omega-3 PUFAs or pubic hair mercury and risk of orthostatic hypotension, except for DPA. Those in the highest vs. the lowest serum DPA tertile had multivariate-adjusted 41% lower odds for orthostatic hypotension (95% confidence interval 7-63%, P-trend=0.02). Serum long-chain omega-3 PUFAs or mercury exposure were not associated with the risk of orthostatic hypotension, except for the inverse association with DPA.

Effect of vitamin D supplementation on orthostatic hypotension: data from the vitamin D in isolated systolic hypertension randomized controlled trial.

OBJECTIVE: Orthostatic hypotension commonly accompanies supine hypertension, and is associated with low 25-hydroxyvitamin D levels. We tested whether high-dose intermittent oral vitamin D therapy could ameliorate orthostatic hypotension in older patients with isolated systolic hypertension. METHODS: We conducted a subgroup analysis of data from a parallel-group, double-blind, randomized, placebo-controlled trial. Patients aged over 70 years with supine office SBP above 140 mmHg and DBP below 90 mmHg received 100 000 units oral vitamin D3 or matching placebo every 3 months for 1 year. Office supine and standing blood pressure were measured at baseline, and 3, 6, 9 and 12 months, along with arterial stiffness and flow-mediated dilatation of the brachial artery. RESULTS: Of 159 patients randomized to the main trial, 75 patients with orthostatic hypotension at baseline were included in this analysis. The mean age was 78 (SD 5) years, baseline blood pressure was 162/76 mmHg and the mean baseline orthostatic fall in blood pressure on standing was 32/5 mmHg. After adjustment for baseline age, 25-hydroxyvitamin D, SBP and orthostatic fall, the fall in SBP was less in the vitamin D group at 3 months [treatment effect 6 mmHg, 95% confidence interval (CI) 0 to 12], but repeated-measures analysis showed no significant treatment effect (3 mmHg for systolic fall, 95% CI -1 to 8; 1 mmHg for diastolic fall, 95% CI -1 to 3). CONCLUSION: Twelve months of intermittent, high-dose oral vitamin D3 did not significantly improve orthostatic hypotension in older patients with isolated systolic hypertension.

Vitamin D and orthostatic hypotension.

INTRODUCTION: we aimed to investigate on the potential relationship between vitamin D and orthostatic hypotension (OH) in a case-control model in older adults. METHODS: all participants were community-dwelling adults who were not taking vitamin D supplements. Cases were subjects aged 64 or older who were diagnosed with OH at a Falls and Blackout Unit. Controls were age- (within 5 years) and gender-matched subjects who had no history of blackouts, falls or orthostatic dizziness in the preceding year. OH was defined according to standard criteria and was diagnosed with an active stand test. Serum vitamin D [25(OH)D] was measured by radioimmunoassay. RESULTS: seventy-six subjects were included in the analysis (38 controls and 38 cases). Twenty-four in each group were female and mean age was between 78 and 79 years. Subjects with OH had lower serum 25(OH)D compared to controls (mean difference = 20.6 nmol/l, P = 0.0002). Lower vitamin D status was associated with an increased risk of OH after adjustment for season, body mass index, presence of stroke, diabetes and angina (P = 0.035) but not with impaired orthostatic haemodynamics. DISCUSSION: findings suggest that vitamin D may play a role in the aetiology of OH. Further studies will be required to explore on this relationship.

Potassium supplementation in the treatment of idiopathic postural hypotension.

We studied the effects of potassium supplementation (60 mmol/day) and matching placebo on the postural blood-pressure fall in ten elderly patients with symptomatic idiopathic postural hypotension in a double-blind, randomized cross-over trial. There was a significant decrease in the orthostatic fall in systolic blood pressure (SBP 33 +/- 5 mmHg to 16 +/- 9 mmHg, p less than 0.01) and in supine SBP (162 +/- 7 to 150 +/- 7 mmHg, p less than 0.01) between placebo and potassium phases. Supine diastolic and erect blood pressures were unchanged, though pulse rate showed a greater orthostatic increase (7 +/- 3 beats/min to 14 +/- 2 beats/min, p less than 0.05) following potassium therapy. No significant changes were seen in intracellular electrolytes, plasma renin activity, aldosterone levels or body weight. Seven patients reported symptomatic improvement with potassium, but none during the placebo phase. Potassium therapy was well tolerated and may be a successful and safe method of treating idiopathic postural hypotension.