Heather Swales

Vitamin D Therapy in Individuals With Prehypertension or Hypertension The DAYLIGHT Trial

Background— A large body of epidemiological and experimental evidence suggests that vitamin D deficiency may promote hypertension. This raises the possibility that vitamin D supplementation could be a simple intervention to reduce blood pressure, but data from prospective, randomized trials are limited. Methods and Results— A double-blind, randomized, controlled trial was conducted at 4 sites in the United States. We enrolled 534 individuals 18 to 50 years of age with low vitamin D status (25-hydroxyvitamin D levels ⩽25 ng/mL) and systolic blood pressure of 120 to 159 mm Hg. Participants were randomized to high-dose (4000 IU/d) versus low-dose (400 IU/d) oral vitamin D3 for 6 months. The primary end point was change in mean 24-hour systolic blood pressure. Secondary end points included change in ambulatory diastolic blood pressure and clinic systolic and diastolic blood pressures. The median age was 38 years, and 62% of participants were men. Forty-six percent of participants were white, and 48% were black. The median 25-hydroxyvitamin D level at baseline was 15.3 ng/mL. Four-hundred fifty-five participants (85%) had at least 1 follow-up blood pressure measurement; 383 participants (72%) completed the full 6-month study. At the end of the study, there was no significant difference in the primary end point (change in mean 24-hour systolic blood pressure, −0.8 versus −1.6 mm Hg in the high-dose and low-dose arms; P=0.71) or in any of the secondary end points. Furthermore, there was no evidence of association between change in 25-hydroxyvitamin D and change in 24-hour systolic blood pressure at 6 months (Spearman correlation coefficient, −0.05, P=0.34). Results were consistent across prespecified subgroups. Conclusions— Vitamin D supplementation did not reduce blood pressure in individuals with prehypertension or stage I hypertension and vitamin D deficiency. Our findings suggest that the association between vitamin D status and elevated blood pressure noted in observational studies is not causal. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01240512.

Vitamin D and cardiovascular disease risk: emerging evidence.

Purpose of review Vitamin D deficiency is common throughout the world, with a particularly high prevalence in northern latitudes and colder climates. Although the best known sequelae of vitamin D deficiency involve the musculoskeletal system, a growing body of evidence suggests that vitamin D status may influence cardiovascular health as well. This review focuses on recent studies linking vitamin D and cardiovascular disease risk, emphasizing the potential relevance to primary prevention. Recent findings There is strong experimental evidence that vitamin D status may influence cardiovascular structure and function. The number of clinical studies has steadily grown in recent years, with the largest number comprising observational studies showing associations between low vitamin D status, the presence of various cardiovascular risk factors, and adverse cardiovascular outcomes. A few small, randomized, controlled studies have been published, but these have been largely inconclusive. Summary Despite substantial clinical evidence linking vitamin D deficiency with increased cardiovascular risk, it remains to be established whether this represents a causal association. Further study is needed with prospective, randomized controlled trials before vitamin D supplementation can be routinely recommended for the primary or secondary prevention of cardiovascular disease.

High-Dose versus Low-Dose Vitamin D Supplementation and Arterial Stiffness among Individuals with Prehypertension and Vitamin D Deficiency

Introduction. Vitamin D deficiency is associated with the onset and progression of hypertension and cardiovascular disease (CVD). However, mechanisms underlying vitamin D deficiency-mediated increased risk of CVD remain unknown. We sought to examine the differential effect of high-dose versus low-dose vitamin D supplementation on markers of arterial stiffness among ~40 vitamin D deficient adults with prehypertension. Methods. Participants were randomized to high-dose (4000 IU/d) versus low-dose (400 IU/d) oral vitamin D3 for 6 months. 24 hr ambulatory blood pressure (BP), carotid-femoral pulse wave velocity, and pulse wave analyses were obtained at baseline and after 6 months of vitamin D supplementation. Results. There were no changes in resting BP or pulse wave velocity over 6 mo regardless of vitamin D dose (all p > 0.202). High-dose vitamin D decreased augmentation index and pressure by 12.3 ± 5.3% (p = 0.047) and 4.0 ± 1.5 mmHg (p = 0.02), respectively. However, these decreases in arterial stiffness were not associated with increases in serum 25-hydroxyvitamin D over 6 mo (p = 0.425). Conclusion. High-dose vitamin D supplementation appears to lower surrogate measures of arterial stiffness but not indices of central pulse wave velocity. Clinical Trial Registration. This trial is registered with www.clinicaltrials.gov (Unique Identifier: NCT01240512).

COMPLEX AORTIC COARCTATION: A MANAGEMENT DILEMMA

Complex congenital heart pathologies can often pose a management challenge. 27 yr old man with history of hypertension presented with fever of 3 week duration. Physical exam revealed 4/6 systolic murmur, and upper-lower extremity BP difference of 58 mmHg. TEE showed perforated anterior mitral

Vitamin D Therapy in Individuals With Prehypertension or HypertensionCLINICAL PERSPECTIVE

Background— A large body of epidemiological and experimental evidence suggests that vitamin D deficiency may promote hypertension. This raises the possibility that vitamin D supplementation could be a simple intervention to reduce blood pressure, but data from prospective, randomized trials are limited. Methods and Results— A double-blind, randomized, controlled trial was conducted at 4 sites in the United States. We enrolled 534 individuals 18 to 50 years of age with low vitamin D status (25-hydroxyvitamin D levels ⩽25 ng/mL) and systolic blood pressure of 120 to 159 mm Hg. Participants were randomized to high-dose (4000 IU/d) versus low-dose (400 IU/d) oral vitamin D3 for 6 months. The primary end point was change in mean 24-hour systolic blood pressure. Secondary end points included change in ambulatory diastolic blood pressure and clinic systolic and diastolic blood pressures. The median age was 38 years, and 62% of participants were men. Forty-six percent of participants were white, and 48% were black. The median 25-hydroxyvitamin D level at baseline was 15.3 ng/mL. Four-hundred fifty-five participants (85%) had at least 1 follow-up blood pressure measurement; 383 participants (72%) completed the full 6-month study. At the end of the study, there was no significant difference in the primary end point (change in mean 24-hour systolic blood pressure, −0.8 versus −1.6 mm Hg in the high-dose and low-dose arms; P=0.71) or in any of the secondary end points. Furthermore, there was no evidence of association between change in 25-hydroxyvitamin D and change in 24-hour systolic blood pressure at 6 months (Spearman correlation coefficient, −0.05, P=0.34). Results were consistent across prespecified subgroups. Conclusions— Vitamin D supplementation did not reduce blood pressure in individuals with prehypertension or stage I hypertension and vitamin D deficiency. Our findings suggest that the association between vitamin D status and elevated blood pressure noted in observational studies is not causal. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01240512.

Vitamin D Therapy in Individuals With Prehypertension or HypertensionCLINICAL PERSPECTIVE: The DAYLIGHT Trial

Background— A large body of epidemiological and experimental evidence suggests that vitamin D deficiency may promote hypertension. This raises the possibility that vitamin D supplementation could be a simple intervention to reduce blood pressure, but data from prospective, randomized trials are limited. Methods and Results— A double-blind, randomized, controlled trial was conducted at 4 sites in the United States. We enrolled 534 individuals 18 to 50 years of age with low vitamin D status (25-hydroxyvitamin D levels ⩽25 ng/mL) and systolic blood pressure of 120 to 159 mm Hg. Participants were randomized to high-dose (4000 IU/d) versus low-dose (400 IU/d) oral vitamin D3 for 6 months. The primary end point was change in mean 24-hour systolic blood pressure. Secondary end points included change in ambulatory diastolic blood pressure and clinic systolic and diastolic blood pressures. The median age was 38 years, and 62% of participants were men. Forty-six percent of participants were white, and 48% were black. The median 25-hydroxyvitamin D level at baseline was 15.3 ng/mL. Four-hundred fifty-five participants (85%) had at least 1 follow-up blood pressure measurement; 383 participants (72%) completed the full 6-month study. At the end of the study, there was no significant difference in the primary end point (change in mean 24-hour systolic blood pressure, −0.8 versus −1.6 mm Hg in the high-dose and low-dose arms; P=0.71) or in any of the secondary end points. Furthermore, there was no evidence of association between change in 25-hydroxyvitamin D and change in 24-hour systolic blood pressure at 6 months (Spearman correlation coefficient, −0.05, P=0.34). Results were consistent across prespecified subgroups. Conclusions— Vitamin D supplementation did not reduce blood pressure in individuals with prehypertension or stage I hypertension and vitamin D deficiency. Our findings suggest that the association between vitamin D status and elevated blood pressure noted in observational studies is not causal. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01240512.