Associations of blood pressure, sunlight, and vitamin D in community-dwelling adults

Brighter nights and darker days predict higher mortality risk: A prospective analysis of personal light exposure in >88,000 individuals

Light enhances or disrupts circadian rhythms, depending on the timing of exposure. Circadian disruption contributes to poor health outcomes that increase mortality risk. Whether personal light exposure predicts mortality risk has not been established. We therefore investigated whether personal day and night light, and light patterns that disrupt circadian rhythms, predicted mortality risk. UK Biobank participants (N = 88,905, 62.4 ± 7.8 y, 57% female) wore light sensors for 1 wk. Day and night light exposures were defined by factor analysis of 24-h light profiles. A computational model of the human circadian pacemaker was applied to model circadian amplitude and phase from light data. Cause-specific mortality was recorded in 3,750 participants across a mean (±SD) follow-up period of 8.0 ± 1.0 y. Individuals with brighter day light had incrementally lower all-cause mortality risk (adjusted-HR ranges: 0.84 to 0.90 [50 to 70th light exposure percentiles], 0.74 to 0.84 [70 to 90th], and 0.66 to 0.83 [90 to 100th]), and those with brighter night light had incrementally higher all-cause mortality risk (aHR ranges: 1.15 to 1.18 [70 to 90th], and 1.21 to 1.34 [90 to 100th]), compared to individuals in darker environments (0 to 50th percentiles). Individuals with lower circadian amplitude (aHR range: 0.90 to 0.96 per SD), earlier circadian phase (aHR range: 1.16 to 1.30), or later circadian phase (aHR range: 1.13 to 1.20) had higher all-cause mortality risks. Day light, night light, and circadian amplitude predicted cardiometabolic mortality, with larger hazard ratios than for mortality by other causes. Findings were robust to adjustment for age, sex, ethnicity, photoperiod, and sociodemographic and lifestyle factors. Minimizing night light, maximizing day light, and keeping regular light-dark patterns that enhance circadian rhythms may promote cardiometabolic health and longevity.

Sunlight: Time for a Rethink?

UVR is a skin carcinogen, yet no studies link sun exposure to increased all-cause mortality. Epidemiological studies from the United Kingdom and Sweden link sun exposure with reduced all-cause, cardiovascular, and cancer mortality. Vitamin D synthesis is dependent on UVB exposure. Individuals with higher serum levels of vitamin D are healthier in many ways, yet multiple trials of oral vitamin D supplementation show little benefit. Growing evidence shows that sunlight has health benefits through vitamin D-independent pathways, such as photomobilization of nitric oxide from cutaneous stores with reduction in cardiovascular morbidity. Sunlight has important systemic health benefit as well as risks.

Bone mineral density parameters and related nutritional factors in vegans, lacto-ovo-vegetarians, and omnivores: a cross-sectional study

Introduction

The growing prevalence of vegetarianism determines the need for comprehensive study of the impact of these diets on health and particularly on bone metabolism. We hypothesized that significant dietary differences between vegans, lacto-ovo-vegetarians, and omnivores also cause significant differences in their nutrient status, which may affect bone health.

Methods

The study assessed dual-energy X-ray absorptiometry parameters in lumbar spine and femoral neck, average nutrient intake, serum nutrient concentrations, serum PTH levels, and urinary pH among 46 vegans, 38 lacto-ovo-vegetarians, and 44 omnivores.

Results

There were no differences in bone mineral density (BMD) between the groups. However, the parathyroid hormone (PTH) levels were still higher in vegans compared to omnivores, despite the same prevalence of hyperparathyroidism in all groups. These findings may probably be explained by the fact that each group had its own "strengths and weaknesses." Thus, vegans and, to a lesser extent, lacto-ovo-vegetarians consumed much more potassium, magnesium, copper, manganese, and vitamins B6, B9, and C. At the same time, the diet of omnivores contained more protein and vitamins D and B12. All the subjects consumed less vitamin D than recommended. More than half of vegans and omnivores had insufficiency or even deficiency of vitamin D in the blood. Low serum concentrations of manganese with its quite adequate intake are also noteworthy: its deficiency was observed in 57% of vegans, 79% of lacto-ovo-vegetarians, and 63% of omnivores.

Discussion

Currently, it is no longer possible to conclude that lacto-ovo-vegetarians have lower BMD than omnivores, as our research supported. Vegans in our study also did not demonstrate lower BMD values, only higher PTH blood concentrations, compared to omnivores, however, a large number of studies, including recent, show the opposite view. In this regard, further large-scale research is required. Vegans and lacto-ovo-vegetarians now have a variety of foods fortified with vitamins D and B12, as well as calcium. There is also a great diversity of ethically sourced dietary supplements. The found low concentrations of manganese require further investigation.

Community gardens and urban agriculture: Healthy environment/healthy citizens

Studies are showing that urban community gardening can improve people's psychological and physiological health in myriad ways. Community gardens increase social capital, provide opportunities for altruism, and create accessible and sustainable food sources in urban environments. The purpose of this study was to explore the mental, social, and physical health benefits of participation in an urban community garden in Edmonton, Canada. A focused ethnography was conducted with surveys and semi-structured interviews. Surveys were sent to volunteers and customers of the Green and Gold Garden (GGG). This was followed by focus group interviews with eight volunteers and four customers. The interview format comprised open-ended questions that encouraged participants to share their perceptions of the health and well-being benefits from being at the GGG. Data were coded via inductive coding, and subsequently categorized into themes via an iterative, reflective process. Four health-related themes were generated from thematic analysis: physical health, social health, mental/emotional health, and connection to the global community. Spending time at the GGG improved the respondents' mental health, even during the COVID-19 pandemic, as they reported feelings of altruism, serenity, and connection with nature. Their social health was improved through gathering with other garden members in a sheltered urban green space within the city limits. This study supports the idea that participation in an urban community garden confers health benefits and engenders a greater awareness of, and appreciation for, the local environment and expands one's scope of care to incorporate planetary health.

Latest Knowledge on the Role of Vitamin D in Hypertension

Hypertension is the third leading cause of the global disease burden, and while populations live longer, adopt more sedentary lifestyles, and become less economically concerned, the prevalence of hypertension is expected to increase. Pathologically elevated blood pressure (BP) is the strongest risk factor for cardiovascular disease (CVD) and related disability, thus making it imperative to treat this disease. Effective standard pharmacological treatments, i.e., diuretics, angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blocker (ARBs), beta-adrenergic receptor blockers (BARBs), and calcium channel blockers (CCBs), are available. Vitamin D (vitD) is known best for its role in bone and mineral homeostasis. Studies with vitamin D receptor (VDR) knockout mice show an increased renin-angiotensin-aldosterone system (RAAS) activity and increased hypertension, suggesting a key role for vitD as a potential antihypertensive agent. Similar studies in humans displayed ambiguous and mixed results. No direct antihypertensive effect was shown, nor a significant impact on the human RAAS. Interestingly, human studies supplementing vitD with other antihypertensive agents reported more promising results. VitD is considered a safe supplement, proposing its great potential as antihypertensive supplement. The aim of this review is to examine the current knowledge about vitD and its role in the treatment of hypertension.

Association of sunshine duration with acute myocardial infarction hospital admissions in Beijing, China: A time-series analysis within-summer

BACKGROUND

Over the years, various epidemiological studies found that acute myocardial infarction (AMI) often shows seasonal rhythm patterning, which is usually influenced by the variations of environmental factors, such as air pollution, ambient temperature, solar activity, relative humidity. However, there are few studies on the impact of sunlight-induced AMI especially in developing countries, and they had inconsistent results. This study aimed to examine within-summer variations in the temporal association between sun exposure and AMI.

METHODS

We obtained hospitalization data for AMI of Beijing during 2013-2019. We used a distributed lag non-linear model (DLNM) combined with a quasi-Poisson regression model to estimate the non-linear lag effects of sunshine duration on AMI incidences. We evaluated the overall effect of AMI admissions with exposure to sunshine duration in the lag 0-21 days.

RESULTS

A total of 45,301 AMI cases were enrolled in our study during summer (June-September). The minimum of the morbidity was during days with a sunshine duration of 3.9 h. We found significant and U-shaped associations between sunshine duration and AMI, and the overall estimated relative risk was 1.29 (95% CI: 1.02,1.62) and 1.69 (95% CI: 1.28,2.24) for short (1st percentile) and long (99th percentile) sunshine duration, respectively. The males and younger people (<65 years) were most susceptible to these effects.

CONCLUSION

Our results suggest that both short and long sunshine duration could increase the risk of AMI admissions, especially for males and younger people. We suggest that public health policymakers should fully consider the balance of the pros and cons of solar exposure, and provide appropriate public health recommendations accordingly to gain the greatest benefits from sunlight.

An Exploration of How Solar Radiation Affects the Seasonal Variation of Human Mortality Rates and the Seasonal Variation in Some Other Common Disorders

Many diseases have large seasonal variations in which winter overall mortality rates are about 25% higher than in summer in mid-latitude countries, with cardiovascular diseases and respiratory infections and conditions accounting for most of the variation. Cancers, by contrast, do not usually have pronounced seasonal variations in incidence or mortality rates. This narrative review examines the epidemiological evidence for seasonal variations in blood pressure, cardiovascular disease rates and respiratory viral infections in relation to atmospheric temperature and humidity, and solar UV exposure through vitamin D production and increased blood concentrations of nitric oxide. However, additional mechanisms most likely exist by which solar radiation reduces the risk of seasonally varying diseases. Some studies have been reported with respect to temperature without considering solar UV doses, although studies regarding solar UV doses, such as for respiratory infections, often consider whether temperature can affect the findings. More research is indicated to evaluate the relative effects of temperature and sun exposure on the seasonality of mortality rates for several diseases. Since solar ultraviolet-B (UVB) doses decrease to vanishingly small values at higher latitudes in winter, the use of safe UVB lamps for indoor use in winter may warrant consideration.

Seasonal Variation: A Non-negligible Factor Associated With Blood Pressure in Patients Undergoing Hemodialysis

Objective

To investigate a seasonal variation in blood pressure (BP) for patients undergoing hemodialysis (HD).

Methods

In this retrospective study, we exported all BP measurements from the information system to investigate a seasonal variation of BP. We also investigated a seasonal variation in BP for patients of different gender types, of different age groups, with diabetic nephropathy (DN), and with non-DN having HD. Multiple linear regression models were used to explore the associations between BP and climatic parameters.

Results

In 2019, a total of 367 patients had received HD therapy in the Longwen HD unit. We included nearly 40,000 pre-dialysis BP measurements. The result of our study demonstrated a clear seasonal variation in pre-dialysis BP in general patients with HD, in male and female patients, and patients with DN and non-DN. December seemed to be a peak in the values of pre-dialysis systolic BP (SBP) and diastolic BP (DBP). The nadir values of pre-dialysis SBP and DBP were observed in June and July, respectively. A difference between peak and nadir values of BP is 3.81/2.20 mmHg in patients undergoing HD. Maximal seasonal variation in BP is 9.03/5.08 mmHg for patients with DN. A significant association of SBP and DBP with climatic parameters was found in this study. Pre-dialysis BP was inversely correlated with outdoor temperature, daytime length, and relative humidity.

Conclusion

A clear seasonal variation in BP is observed for patients with HD. Pre-dialysis SBP and DBP are inversely associated with outdoor temperature, daytime length, and relative humidity. The magnitude of a seasonal variation in BP increases in patients with DN.

Community planning for a "healthy built environment" via a human-environment nexus? A multifactorial assessment of environmental characteristics and age-specific stroke mortality in Hong Kong

With the prevalence of stroke rising due to both aging societies and more people getting strokes at a younger age, a comprehensive investigation into the relationship between urban characteristics and age-specific stroke mortality for the development of a healthy built environment is necessary. Specifically, assessment of various dimensions of urban characteristics (e.g. short-term environmental change, long-term environmental conditions) is needed for healthy built environment designs and protocols. A multifactorial assessment was conducted to evaluate associations between environmental and sociodemographic characteristics with age-stroke mortality in Hong Kong. We found that short-term (and temporally varying) daily PM₁₀, older age and being female were more strongly associated with all types of stroke deaths compared to all-cause deaths in general. Colder days, being employed and being married were more strongly associated with hemorrhagic stroke deaths in general. Long-term (and spatially varying) regional-level air pollution were more strongly associated with non-hemorrhagic stroke deaths in general. These associations varied by age. Employment (manual workers) and low education were risk factors for stroke mortality at younger ages (age <65). Greenness and open space did not have a significant association with stroke mortality. Since a significant connection was expected, this leads to questions about the health-inducing efficacy of Hong Kong's compact open spaces (natural greenery being limited to steep slopes, and extensive impervious surfaces on public open spaces). In conclusion, urban plans and designs for stroke mortality prevention should implement age-specific health care to neighborhoods with particular population segments.

The influence of vegetarian and vegan diets on the state of bone mineral density in humans

There are so many literatures about vegetarians being less prone to chronic, noninfectious diseases, which are, however, the main cause of the decline in quality of life and mortality in developed countries.However, according to various scientific sources, vegetarian and especially vegan diets often contain less saturated fats, protein, calcium, vitamins D and B12, or long-chain ω-3 PUFAs. One of the most common pathology associated with a predominantly plant diet is osteopenia and osteoporosis. An analysis of 13 studies has shown that vegetarians and vegans are at a higher risk of reducing of bone mineral density, thereby increasing the incidence of fractures.At the same time, plant-based diets are usually richer in many other micronutrients important for bone health: vitamins C and K, carotenoids, potassium, magnesium, manganese, copper, or silicon. Moreover, with the deepening of our knowledge about the role of nutrients in the body and the features of the nutritional status of the population, the quality of vegetarian and vegan diets also increases. They are less and less prone to micronutrient deficiencies. Recent studies show that BMD, as well as the risk of osteoporotic fractures, at least in vegetarians, equaled these indicators in omnivores.

The effect of ultraviolet irradiation compared to oral vitamin D supplementation on blood pressure of nursing home residents with dementia

Background

Observational studies have reported an inverse association between ultraviolet (UV) radiation and hypertension. The aim of this study was to assess differences in blood pressure changes between persons with dementia receiving UV light versus vitamin D (VD) supplementation.

Methods

Post-hoc analysis of randomized controlled trial data concerning nursing home residents with dementia (N = 61; 41 women, mean age 84.8 years). The participants received half-body UV irradiation, twice weekly over 6 months, at one standard erythema dose (UV group, n = 22) or 5600 international units of cholecalciferol once a week (VD group, n = 39). Short-term effects were evaluated after 1 month and long-term effects after 3 and 6 months. Differences in blood pressure changes were assessed using linear mixed models.

Results

With the VD group as a reference, the estimated difference in mean change of systolic blood pressure was − 26.0 mmHg [95% confidence interval (CI) -39.9, − 12.1, p = .000] at 1 month, 4.5 mmHg (95% CI -6.8, 15.9, p = 0.432) at 3 months, and 0.1 (95% CI -14.1, 14.3, p = 0.83) at 6 months. The estimated difference in diastolic blood pressure was − 10.0 mmHg (95% CI -19.2, − 0.7, p = 0.035) at 1 month, 3.6 mmHg (95% CI -4.1, 11.2, p = 0.358) at 3 months, and 2.7 (95% CI -6.8, 12.1, p = 0.580) at 6 months.

Conclusions

UV light had only a short-term effect but not a long-term effect on blood pressure reduction compared to VD use in this sample of normotensive to mild hypertensive nursing home residents with dementia. Future studies will be needed to determine the effect of UV light in different samples of the population and especially in a population with hypertension.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02538-7.

Prenatal exposure to solar radiation and hypertensive disorders of pregnancy

OBJECTIVE

To examine the association between prenatal exposure to solar radiation and hypertensive disorders of pregnancy (HDP).

DESIGN

A multicentre retrospective study.

SETTING

19 hospitals in the USA.

POPULATION

205 888 women with singleton gestation from the Consortium on Safe Labor (2002-2008).

MAIN OUTCOME MEASURES

Gestational hypertension, pre-eclampsia/eclampsia, and pre-eclampsia superimposed on chronic hypertension.

METHODS

Medical records of the participants were linked to solar radiation obtained from the National Solar Radiation Database. Average daily solar radiation of each woman was estimated over the entire pregnancy period and over three trimesters during pregnancy according to hospital sites. Generalised estimated equation was applied to investigate the relationship between quartiles of average daily solar radiation and HDP. Restricted cubic spline was applied to assess the nonlinear associations.

RESULTS

Higher average solar radiation during the entire pregnancy was associated with reduced risks of HDP. Compared with the 1st quartile of solar radiation during the entire pregnancy, odds ratios (ORs) of the 2nd, 3rd and 4th quartiles were respectively 0.80 (95% CI 0.72-0.90), 0.63 (95% CI 0.55-0.73), 0.65 (95% CI 0.54-0.78) for gestational hypertension; 0.66 (95% CI 0.57-0.76), 0.61 (95% CI 0.51-0.73), 0.77 (95% CI 0.62-0.95) for pre-eclampsia, and 0.44 (95% CI 0.36-0.55), 0.42 (95% CI 0.35-0.49), 0.60 (95% CI 0.46-0.78) for superimposed pre-eclampsia.

CONCLUSION

Exposure to higher daily solar radiation during pregnancy is associated with a decreased risk of HDP. The protective effect was stronger for superimposed pre-eclampsia than for pre-eclampsia or gestational hypertension.

TWEETABLE ABSTRACT

Exposure to higher daily solar radiation during pregnancy is associated with a decreased risk of HDP.

The Healthy Taiwanese Eating Approach is inversely associated with all-cause and cause-specific mortality: A prospective study on the Nutrition and Health Survey in Taiwan, 1993-1996

Background

Few longitudinal studies have investigated the association between foods/dietary pattern and mortality risk in the Asian population. We investigated the prospective association between foods/dietary pattern and risk of death among ethnic Chinese adults in Taiwan.

Methods

The study population included 2475 young and middle-aged adults (aged 18–65 years at baseline) who completed the questionnaires and physical examinations in the Nutrition and Health Survey in Taiwan from 1993 to 1996. A food frequency questionnaire was administered to assess food consumption habits in a face-to-face interview. With survey data linked to the Taiwanese Death Registry, Cox proportional hazard model was used to identify the foods associated with all-cause mortality(followed until 2012), which were then tallied to calculate a dietary pattern score called Taiwanese Eating Approach(TEA) score. The TEA scores were then associated with various kinds of mortality outcomes. In addition, data from 431 elders (aged≥65 yrs) with 288 death endpoints were used to conduct a sensitivity analysis.

Results

A total of 385(15.6%) participants died (111 cardiovascular related deaths and 122 cancer related deaths) during the 17.8-year follow-up period(41274 person-years). Twelve foods (9 inverse [vegetables/fish/milk/tea](+1) and 3 positive[fatty meats/fermented vegetables/sweet drinks](-1)) were significantly associated with all-cause mortality risk. All adults were grouped by their cumulative food score into three diet groups: poor diet(29.3% of all subjects), average diet(44.0%), and healthy diet(26.70%). The better the diet, the lower the total, cardiovascular, and other cause mortality outcomes (trend-p < .001). The hazard ratio for the healthy diet was 0.64 (95% confidence interval:0.47–0.87) for total mortality, and 0.52(0.28–0.95) for cardiovascular death, compared with the poor diet in the multivariable models. This phenomenon was also seen in older adults for all-cause, cancer, and other cause mortalities.

Conclusion

Consuming a healthy Taiwanese Eating Approach (TEA) diet is negatively associated with all-cause, cardiovascular, and other-cause mortalities in Taiwan.

Low sun exposure habits is associated with a dose-dependent increased risk of hypertension: a report from the large MISS cohort

In prospective observational cohort studies, increasing sun exposure habits have been associated with reduced risk of cardiovascular mortality. Our aim was to assess possible observational mechanisms for this phenomenon. A written questionnaire was answered by 23,593 women in the year 2000 regarding risk factors for melanoma, including factors of possible interest for hypertension, such as detailed sun exposure habits, hypertension, marital status, education, smoking, alcohol consumption, BMI, exercise, and chronic high stress. Hypertension was measured by the proxy "use of hypertension medication" 2005-2007, and high stress by "need of anti-depressive medication". Sun exposure habits was assessed by the number of `yes' to the following questions; Do you sunbath during summer?, During winter vacation?, Do you travel south to sunbath?, Or do you use sun bed? Women answering 'yes' on one or two questions had moderate and those answering 'yes' on three or four as having greatest sun exposure. The main outcome was the risk of hypertension by sun exposure habits adjusted for confounding. As compared to those women with the greatest sun exposure, women with low and moderate sun exposure were at 41% and 15% higher odds of hypertension (OR 1.41, 95% CI 1.3‒1.6, p < 0.001 and OR 1.15, 95% CI 1.1‒1.2, p < 0.001), respectively. There was a strong age-related increased risk of hypertension. Other risk factors for hypertension were lack of exercise (OR 1.36), a non-fair phenotype (OR 1.08), chronic high stress level (OR 1.8), and lack of university education (OR 1.3). We conclude that in our observational design sun exposure was associated with a dose-dependent reduced risk of hypertension, which might partly explain the fewer deaths of cardiovascular disease with increasing sun exposure.

Effect of Short-Term Sunlight Exposure on Blood Pressure and Pulse Rate in Vitamin D3-Insufficient, Prehypertensive Patients: A Pilot Study

INTRODUCTION

This study was conducted to evaluate the effect of short-term sunlight exposure on blood pressure (BP) and pulse rate (PR) in vitamin D3-insufficient, prehypertensive patients.

METHODS

Twenty prehypertensive male participants were prospectively enrolled in this pilot study. BP and PR were measured using 24-hour ambulatory BP monitoring and endocrine biomarkers were assessed.

RESULTS

Sunlight exposure decreased 24-hour systolic BP (SBP), diastolic BP (DBP), and PR (SBP: 132.6 mm Hg to 129.3 mm Hg, DBP: 77.6 mm Hg to 75.7 mm Hg, and PR: 76.1 bpm to 71.3 bpm, p values: 0.0011, 0.0012, and <0.0001, respectively). The decrement patterns of SBP, DBP, and PR during nighttime (SBP: 123.5 mm Hg to 117.9 mm Hg, DBP: 72.2 mm Hg to 68.0 mm Hg, and PR: 68.2 bpm to 59.1 bpm, p values: 0.0015, 0.0003, and <0.0001, respectively) were more profound compared between daytime and nighttime. Blood levels of 25-hydroxyvitamin D3 were significantly increased (p = 0.0001) but aldosterone levels were significantly decreased (p = 0.0014) after sunlight exposure. In addition, an inverse relationship between 25-hydroxyvitamin D3 and aldosterone levels was observed (R = -0.4709, p = 0.0419).

DISCUSSION/CONCLUSION

The pilot study gives promising results that it is worthwhile to evaluate short-term sunlight exposure as a potentially effective approach in decreasing BP and PR in 25-hydroxyvitamin D3-insufficient prehypertensive patients in a larger trial with a control group.

Vitamin D and Arterial Hypertension: Facts and Myths

PURPOSE OF REVIEW

Vitamin D and its derivatives are biologically active fat-soluble steroid hormones, which are transcription factors for numerous genes. The results of several observational studies suggest the relationship between plasma concentration of vitamin D and the risk of arterial hypertension, as well as between the intensity of insolation and the risk of arterial hypertension.

RECENT FINDINGS

Based on the results of the abovementioned studies, it was hypothesized that vitamin D is characterized by the antihypertensive properties. Animal experiments have shown that vitamin D reduces activity of the renin-angiotensin-aldosterone system and improves vasorelaxation of blood vessels. Results of clinical studies did not confirm these results. Moreover in interventional clinical trials, it was documented that supplementation of vitamin D did not reduce blood pressure. The influence of exposure to sunshine at different wave lengths on blood pressure was examined in clinical studies and it was found that ultraviolet A radiation (UVA) lead to the release of nitric oxide from the skin. This might explain lower level of blood pressure in subjects from the regions with a higher rate of insolation. The aim of this review is to summarize current knowledge concerning the relationship between vitamin D and arterial hypertension based on both observational and interventional studies.

Association of sun and UV exposure with blood pressure and cardiovascular disease: A systematic review

BACKGROUND

Ecological studies show that sun or ultraviolet (UV) exposure have inverse associations with blood pressure (BP) and cardiovascular disease (CVD). Although sunlight is the primary source of vitamin D, recent meta-analyses of clinical trials have not reported a beneficial effect from vitamin D supplementation on BP or CVD. Sunlight may have beneficial effects independent of vitamin D. We carried out a systematic review to appraise the extent and quality of the evidence from human studies.

METHODS

Observational and interventional studies that measured sun or UV exposure, along with BP or CVD, were selected after searching databases.

RESULTS

Identified studies could not be combined quantitatively in meta-analysis because of different exposure measures. Solar exposure was inversely associated with BP in 3 out of 4 cross-sectional publications, and with CVD and/or total mortality in 5 out of 6 publications of cohort studies. Two of the cohort studies reported inverse associations between sun exposure and CVD, after adjusting for serum 25-hydroxyvitamin D. Five clinical trials with an appropriate control group were identified, the outcome being BP. Two trials compared UVB with UVA (as control), with only one finding a significant reduction in BP (after 6 weeks). Three trials compared short-term UVA exposure (<30 min) with placebo (or crossover control), of which two reported short-term lowering of BP.

CONCLUSION

This review has identified a small body of evidence that suggests sun exposure protects against high BP and CVD, but further research is required to determine if this is independent of vitamin D.

The effect of VDR gene polymorphisms and vitamin D level on blood pressure, risk of preeclampsia, gestational age, and body mass index

We investigated the influence of vitamin D receptor (VDR) polymorphisms and vitamin D level on the blood pressure and the risk of preeclampsia. In a case-control study, 200 pregnant women, including 100 individuals with preeclampsia along with 100 healthy pregnant women, were studied for VDR FokI, TaqI, and BmsI polymorphisms and serum 25 (OH)-D level using polymerase chain reaction-restriction fragment length polymorphism method and commercial kit, respectively. The mean level of 25 (OH)-D in preeclamptic patients was significantly lower (16.6 ± 4.2 ng/mL, P < 0.001) compared with controls (19.6 ± 3.8 ng/mL). Among all women, a significantly higher systolic blood pressure and before-pregnancy body mass index and also lower gestational age were observed in the presence of 25 (OH)-D level < 20 ng/mL compared with the 20 to 30 ng/mL. A significantly higher frequency of VDR FokI C allele in preeclamptic patients (83%) than controls (74%) was associated with a 1.72-fold increased risk of preeclampsia. In all the studied individuals, the systolic and diastolic blood pressures were significantly higher in the presence of the FokI CC genotype compared with the TC and TT+TC genotypes. Neither VDR Taq1 nor VDR BmsI was associated with the risk of preeclampsia. The haplotype FokI C, TaqI C and BmsI A (CCA) compared with haplotype CTG increased the risk of preeclampsia by 1.4-fold (P = 0.33). Our study suggests an association between VDR FokI polymorphism and an insufficient serum level of 25 (OH)-D with the risk of preeclampsia and also the influence of insufficient 25 (OH)-D level and VDR FokI polymorphism on maternal factors, including blood pressure.

Vitamin D deficiency in relation to the poor functional outcomes in nondiabetic patients with ischemic stroke

To assess the hypothesis that vitamin D, reflected by 25-hydroxyvitamin D (25(OH) D) would be associated with higher risk of poor functional outcomes amongst nondiabetic stroke patients. The present study was conducted in Nanchang, China. Serum concentration of 25(OH) D and National Institutes of Health Stroke Scale (NIHSS) were measured at the time of admission. Functional outcome was measured by modified Rankin scale (mRS) at 1 year after admission. Multivariate analyses were performed using logistic regression models. The cut point of 25(OH) D level for vitamin D deficiency was 20 ng/ml. In the present study, 266 nondiabetic subjects with stroke were included; 149 out of the 266 patients were defined as vitamin D deficiency (56%). The poor outcome distribution across the 25(OH) D quartiles ranged between 64% (first quartile) and 13% (fourth quartile). In those 149 patients with vitamin D deficiency, 75 patients were defined as poor functional outcomes, giving a prevalence rate of 50% (95% confidence interval (CI): 42–58%). In multivariate analysis models, for vitamin D deficiency, the adjusted risk of poor functional outcomes and mortality increased by 220% (odds ratio (OR): 3.2; 95% CI: 1.7–4.2, P<0.001) and 290% (OR: 3.9; 95% CI: 2.1–5.8, P<0.001), respectively. Vitamin D deficiency is associated with an increased risk of poor functional outcome events in Chinese nondiabetic stroke individuals.

Anti-hypertensive drugs and skin cancer risk: a review of the literature and meta-analysis

INTRODUCTION

Several anti-hypertensive drugs have photosensitizing properties, however it remains unclear whether long-term users of these drugs are also at increased risk of skin malignancies. We conducted a literature review and meta-analysis on the association between use of anti-hypertensive drugs and the risk of cutaneous melanoma and non-melanoma skin cancer (NMSC).

METHODS

We searched PubMed, EMBASE, Google Scholar and the Cochrane Library, and included observational and experimental epidemiological studies published until February 28th, 2017. We calculated summary relative risk (SRR) and 95% confidence intervals (95% CI) through random effect models to estimate the risk of skin malignancies among users of the following classes of anti-hypertensive drugs: thiazide diuretics, angiotensin converting enzyme inhibitors (ACEi), angiotensin receptor blockers (ARB), calcium channel blockers (CCB) and β-blockers. We conducted sub-group and sensitivity analysis to explore causes of between-studies heterogeneity, and assessed publication bias using a funnel-plot based approach.

RESULTS

Nineteen independent studies were included in the meta-analysis. CCB users were at increased skin cancer risk (SRR 1.14, 95% CI 1.07-1.21), and β-blockers users were at increased risk of developing cutaneous melanoma (SRR 1.21, 95% CI 1.05-1.40), with acceptable between-studies heterogeneity (I2 < 50%). There was no association between thiazide diuretics, ACEi or ARB use and skin cancer risk. We found no evidence of publication bias affecting the results.

CONCLUSION

Family doctors and clinicians should inform their patients about the increased risk of skin cancer associated with the use of CCB and β-blockers and instruct them to perform periodic skin self-examination. Further studies are warranted to elucidate the observed associations.

Vitamin D and Blood Pressure Among U.S. Adults: A Cross-sectional Examination by Race/Ethnicity and Gender

INTRODUCTION

The cross-sectional association of serum vitamin D levels with blood pressure and hypertension status among a representative sample of U.S. adults was examined.

METHODS

Participants of the National Health and Nutrition Examination Survey from 2001 to 2010 were included in these analyses. Harmonizing of the vitamin D levels from 2001 to 2006 with vitamin D measurement from 2007 to 2010 was done using regression equations released by the Centers for Disease Control and Prevention. Use of vitamin D supplements was assessed for all participants. Statistical analyses included examination of linear association of vitamin D levels with blood pressure and non-linear cubic splines with hypertension in overall population, by gender, and by race/ethnicity.

RESULTS

With every 10 nmol/L higher vitamin D, systolic blood pressure decreased by 0.19 mmHg in this population (p<0.01). In fully adjusted stratified analyses, this association was present among females (-0.25 mmHg, p<0.01) and non-Hispanic whites (0.22 mmHg, p<0.01). After race/ethnic and gender stratification, this association was observed among non-Hispanic white females (0.26 mmHg, p=0.01), non-Hispanic black females (0.65 mmHg, p=0.02), and marginally significant among Hispanic males (0.33 mmHg, p=0.07). Non-parametric assessment with cubic splines show that vitamin D has an inverse association with odds of hypertension up to 100 nmol/L with no apparent benefit at higher levels in overall population, and even lower threshold levels of vitamin D in non-Hispanic blacks (50 nmol/L) and Hispanic Americans (70 nmol/L).

CONCLUSIONS

Significant race/ethnic and gender differences exist in the association of vitamin D and systolic blood pressure. Odds for hypertension are reduced significantly at higher vitamin D levels, but this benefit plateaus at very high vitamin D levels.

Seasonal variations of U.S. mortality rates: Roles of solar ultraviolet-B doses, vitamin D, gene exp ression, and infections

Death rates in the U.S. show a pronounced seasonality. The broad seasonal variation shows about 25% higher death rates in winter than in summer with an additional few percent increase associated with the Christmas and New Year's holidays. A pronounced increase in death rates also starts in mid-September, shortly after the school year begins. The causes of death with large contributions to the observed seasonality include diseases of the circulatory system; the respiratory system; the digestive system; and endocrine, nutritional, and metabolic diseases. Researchers have identified several factors showing seasonal variation that could possibly explain the seasonal variations in mortality rate. These factors include seasonal variations in solar ultraviolet-B(UVB) doses and serum 25-hydroxyvitamin D [25(OH)D] concentrations, gene expression, ambient temperature and humidity, UVB effects on environmental pathogen load, environmental pollutants and allergens, and photoperiod (or length of day). The factors with the strongest support in this analysis are seasonal variations in solar UVB doses and 25(OH)D concentrations. In the U.S., population mean 25(OH)D concentrations range from 21ng/mL in March to 28ng/mL in August. Measures to ensure that all people had 25(OH)D concentrations >36ng/mL year round would probably reduce death rates significantly.

Elevated systolic blood pressure of children in the United States is associated with low serum 25-hydroxyvitamin D concentrations related to body mass index: National Health and Examination Survey 2007-2010

A negative association between serum 25-hydroxyvitamn D (25[OH]D) concentrations and blood pressure has been found in adults; whether a similar relationship exists in children remains unclear. We hypothesized that serum 25(OH)D concentrations of children would negatively correlate with blood pressure. Using a nationally representative sample of children aged 8 to 18years from the National Health and Nutrition Examination Survey 2007-2010 (n=2908), we compared serum 25(OH)D levels with diastolic and systolic blood pressure by vitamin D nutritional status categories. A high percentage of children were either vitamin D deficient (28.8%) or vitamin D insufficient (48.8%). Prehypertension was defined as blood pressure as ≥90th to <95th percentile and hypertension as ≥95th percentile by age, height, and sex national blood pressure percentile norms for children. Vitamin D-deficient children aged 8 to 13years had higher systolic blood pressure (104.8±0.7mm Hg) than did vitamin D-sufficient children (102.3±0.6mmHg; P<.05). Controlling for age, sex, race/ethnicity, and income, systolic blood pressure was inversely associated with serum 25(OH)D concentrations (P<.03), but not when also controlling for body mass index (P=.63). A higher percentage of vitamin D-deficient and vitamin D-insufficient children (1.7%) vs vitamin D-sufficient children (0.6%) had prehypertension or hypertension. In conclusion, the association of low serum 25(OH)D concentrations with elevated systolic blood pressure in children is likely related to body weight and markers of adiposity.

Lifestyle Approaches to White Coat Hypertension

This case presentation illustrates the importance of 24 hour ambulatory blood pressure monitoring in patients with white coat hypertension, as many progress into sustained hypertension over time. Also, it serves as a reminder not to overlook a possible underlying sleep breathing disorder in patients who are not obese or fatigued. Finally, the case provides an opportunity to review the value of non-pharmacological and lifestyle approaches to the treatment of both white coat hypertension and sustained hypertension.