Is sunlight good for our heart?

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.

Ultraviolet irradiation benefits left ventricular hypertrophy and mitochondrial morphology of cardiomyocytes in hypertensive rats

Insufficient exposure to sunlight increases the risk of cardiovascular diseases. Hypertensive left ventricular (LV) hypertrophy exacerbates the risks of myocardial ischemia, ventricular arrhythmias, sudden cardiac death, and heart failure. This study aimed to determine the effects of ultraviolet (UV) irradiation on LV hypertrophy and mitochondrial morphology. Eighteen 7-week-old Dahl salt-sensitive (Dahl S) rats were categorized into three groups (n = 6 each) and fed sodium chloride (NaCl) diets, as follows: UV-irradiated [UVB+A (+), 8% NaCl], non-UV-irradiated [UV (-), 8% NaCl], and control [UV (-), 0.3% NaCl]. UV irradiation was administered at a low intensity of 100 mJ/cm2 for 6 days per week. Echocardiography and mitochondrial analyses were performed to evaluate LV hypertrophy and cardiomyocytes, and skin tissues were stained with hematoxylin and eosin to assess the pathological abnormalities at 12 weeks of age. LV mass was significantly reduced in the UVB+A (+) and control groups compared to that in the UV (-) group. Mitochondrial structural abnormalities in cardiomyocytes were observed only in the UV (-) group, but not in the UVB+A (+) or control group. Pathological skin abnormalities were not observed in any of the three groups. These findings suggest the potential benefits of UV irradiation in hypertensive models.

All-Cause and Cause-Specific Mortality among Patients with Vitiligo: A Nationwide Population-Based Study in Korea

Vitiligo is a common autoimmune skin disorder; however, there is limited information about risks of mortality among patients with vitiligo. Therefore, we aimed to investigate the mortality in patients with vitiligo. A population-based cohort study was conducted using the data linkage of the National Health Insurance Service database and the National Death Registry. Patients with incident vitiligo were matched with sociodemographic factors-matched controls without vitiligo in a 1:5 ratio. All-cause and cause-specific mortalities were compared between patients with vitiligo and controls. In total, 107,424 patients with incident vitiligo and 537,120 matched controls were included. The mortality rates were 34.8 and 45.3 per 10,000 person-years in patients and controls, respectively. Patients with vitiligo showed a significantly lower risk of mortality (adjusted hazard ratio = 0.75, 95% confidence interval = 0.72-0.78). The cause-specific mortality from infectious diseases, oncologic diseases, hematologic diseases, endocrine diseases, neurologic diseases, cardiovascular diseases, respiratory diseases, and renal/urogenital disease was significantly lower in patients with vitiligo. Patients with vitiligo were associated with a lower risk of mortality, suggesting that vitiligo-associated autoimmunity might contribute to reduced morbidity and mortality.

In-vitro antiplatelet effect of melatonin in healthy individuals and patients with type 2 diabetes mellitus

PURPOSE

The incidence of acute myocardial infarctions (AMI) shows circadian variation typically peaking during morning hours with a decline at night. However, this variation does not occur in patients with diabetes mellitus (DM). The night's decline of AMI may be partially explained by melatonin-related platelet inhibition. Whether this effect is absent in diabetic patients is unknown. The aim was to study the effect of melatonin on in-vitro platelet aggregation in healthy individuals and patients with type 2 DM.

METHODS

Platelet aggregation was measured in blood samples from healthy individuals (n = 15) and type 2 DM patients (n = 15) using multiple electrode aggregometry. Adenosine diphosphate (ADP), arachidonic acid (ASPI) and thrombin (TRAP) were used as agonists. Aggregability for each subject was tested after adding melatonin in two concentrations.

RESULTS

In healthy individuals, melatonin inhibited platelet aggregation in both higher (10-5 M) and lower concentrations (10-9 M) induced by ADP, ASPI, and TRAP (p < 0.001, p = 0.002, p = 0.029, respectively). In DM patients, melatonin did not affect platelet aggregation in both concentrations induced by ADP, ASPI, and TRAP. Melatonin decreased platelet aggregation induced by ADP, ASPI, and TRAP significantly more in healthy individuals compared to patients with DM. (p = 0.005, p = 0.045 and p = 0.048, respectively).

CONCLUSION

Platelet aggregation was inhibited by melatonin in healthy individuals. In-vitro antiplatelet effect of melatonin in type 2 DM patients is significantly attenuated.

Impact of ultraviolet radiation on cardiovascular and metabolic disorders: The role of nitric oxide and vitamin D

BACKGROUND/PURPOSE

Ultraviolet (UV) radiation has both harmful and beneficial effects on human skin and health. It causes skin damage, aging, and cancer; however, it is also a primary source of vitamin D. Additionally, UV radiation can impact energy metabolism and has protective effects on several cardiovascular and metabolic disorders in mice and humans. However, the mechanisms of UV protection against these diseases have not been clearly identified.

METHODS

This review summarizes the systemic effects of UV radiation on hypertension and several metabolic diseases such as obesity, diabetes, and nonalcoholic fatty liver disease (NAFLD) in mice, and we also consider the mechanisms of action of the related regulators nitric oxide (NO) and vitamin D.

RESULTS

UV exposure can lower blood pressure and prevent the development of cardiovascular diseases and metabolic disorders, such as metabolic syndrome, obesity, and type 2 diabetes, primarily through mechanisms that depend on UV-induced NO. UV radiation may also effectively delay the onset of type 1 diabetes through mechanisms that rely on UV-induced vitamin D. UV-induced NO and vitamin D play roles in preventing and slowing the progression of NAFLD.

CONCLUSION

UV exposure is a promising nonpharmacological intervention for cardiovascular and metabolic disorders. NO and vitamin D may play a crucial role in mediating these effects. However, further investigations are required to elucidate the exact mechanisms and determine the optimal dosage and exposure duration of UV radiation.

Meteorological Influence on Atrial Fibrillation and Flutter: A Nationwide Observational Study in South Korea (2010-2022)

Background and rationale The impact of meteorological factors, including atmospheric temperature, humidity, and wind speed, on the incidence of atrial fibrillation and flutter (AF) has been the subject of several studies, but the findings have been inconsistent. Given the complex and multifaceted nature of this relationship, a larger-scale study was necessary to provide sufficient statistical power and elucidate potential associations between them. The aim of this study was, thus, to investigate the potential associations between meteorological factors and the incidence of AF. Methods The South Korean government provides open access to national health insurance and weather data for its citizens; the data was available from January 2010 to July 2022. The national health insurance data includes the monthly number of patients diagnosed with a specific condition, reflecting the incidence and prevalence of the condition. Pearson correlation analyses were performed using the statistical analysis software, SAS® OnDemand for Academics (SAS Institute Inc., Cary, North Carolina, United States), to examine the association between each month's national average climate data and the number of patients diagnosed with AF. Results The number of patients diagnosed with AF in the total population showed a statistically significant correlation only with average wind speed (correlation coefficient (r)=-0.42, 95%CI -0.55 to -0.28, p<0.001) and sunshine duration (r=0.27, 95%CI 0.12 to 0.41, p<0.001). Among females aged 20-24 years, there was a statistically significant association with other variables, including average temperature, precipitation, humidity, and atmospheric pressure (p<0.05). Diurnal temperature variation showed inconsistent associations across different age and sex groups. Conclusion The number of patients diagnosed with AF is negatively correlated with average wind speed and positively correlated with sunshine duration in the general population, particularly among the elderly. There was no significant association between the number of patients diagnosed with AF and average temperature, precipitation, or humidity, except for females aged 20-24 years, who exhibited a significant association with these variables. However, it is important to note that these correlations do not establish causality.

Cloudy or sunny? Effects of different environmental types of urban green spaces on public physiological and psychological health under two weather conditions

Numerous studies have demonstrated that urban green spaces (UGSs) benefit human health, but few have focused on the influence of weather on environmental restorativeness. This study assessed how different weather conditions and environments affect human health. We exposed 50 participants to different UGS environments under cloudy and sunny conditions and collected physiological, psychological and aesthetic preference data. The result showed that the physical and mental benefits of UGSs were stronger on sunny days (pulse: [t = 2.169, p < 0.05]; positive affect: [Z = -10.299, p < 0.001]; perceived restortiveness: [Z = -3.224, p < 0.01]). The spaces with exposed sky had greater physiological restorativeness on sunny days; the spaces with calm water had greater emotional restorativeness on cloudy days, and natural spaces with less sky exposure had greater perceived restoration in both weather conditions. The spaces with water and less sky exposure promoted psychophysiological restoration in both weather conditions. This study demonstrates that weather significantly influences the restorative potential of UGSs, and there are also restorative variations in different green space environments under two weather conditions. In future UGS planning practices, it would be advisable to select appropriate environmental types and features based on the climatic characteristics of different regions. For instance, in areas with frequent overcast conditions, incorporating serene water bodies could be advantageous, while regions with predominantly sunny weather should encompass spaces with expansive sky views. By conducting comprehensive research on restoration environments that take weather conditions into account, new insights and nature-based solutions can be provided for creating healthy human habitats in the context of global climate change.

Enhancement of Nitric Oxide Bioavailability by Modulation of Cutaneous Nitric Oxide Stores

The generation of nitric oxide (NO) in the skin plays a critical role in wound healing and the response to several stimuli, such as UV exposure, heat, infection, and inflammation. Furthermore, in the human body, NO is involved in vascular homeostasis and the regulation of blood pressure. Physiologically, a family of enzymes termed nitric oxide synthases (NOS) generates NO. In addition, there are many methods of non-enzymatic/NOS-independent NO generation, e.g., the reduction of NO derivates (NODs) such as nitrite, nitrate, and nitrosylated proteins under certain conditions. The skin is the largest and heaviest human organ and contains a comparatively high concentration of these NODs; therefore, it represents a promising target for many therapeutic strategies for NO-dependent pathological conditions. In this review, we give an overview of how the cutaneous NOD stores can be targeted and modulated, leading to a further accumulation of NO-related compounds and/or the local and systemic release of bioactive NO, and eventually, NO-related physiological effects with a potential therapeutical use for diseases such as hypertension, disturbed microcirculation, impaired wound healing, and skin infections.

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.

Associations Between Vitamin D Levels and Risk of Heart Failure: A Bidirectional Mendelian Randomization Study

Background

Although studies suggest that concentrations of serum 25-hydroxyvitamin D (25(OH)D) are lower in individuals with Heart Failure (HF), the beneficial effects of vitamin D supplementation are controversial. Therefore, in this study, we aimed to determine whether there is a causal relationship between serum Vitamin D (VD) levels and HF.

Methods

We obtained genetic instruments from the largest available genome-wide association study (GWAS) of European descent for 25(OH)D (443, 734 individuals) to investigate the association with HF (47,309 cases, 930,014 controls), and vice versa. Two-sample bidirectional Mendelian Randomization (MR) analysis was performed to infer the causality. In addition to the primary analysis using inverse variance-weighted (IVW) MR, we applied five additional methods to control for pleiotropy [MR-Egger, weighted median, Maximum-likelihood, MR-robust adjusted profile score (MR-RAPS) and MR-pleiotropy residual sum and outlier (MR-PRESSO)] and compared their respective MR estimates. We also performed a sensitivity analysis to ensure that our results were robust.

Results

Mendelian randomized analysis showed that increased serum 25(OH)D was associated with a lower risk of HF in the IVW method (odds ratio [OR] = 0. 81;95%CI, 0.70–0.94, P = 0.006). In the reverse MR analyses, the genetic predisposition to HF was negatively correlated with serum 25(OH)D level (OR = 0. 89;95%CI, (0.82–0.97), P = 0.009).

Conclusion

Our study revealed the possible causal role of 25(OH)D on decreasing the risk for HF. Meanwhile, reverse MR analysis suggested that HF may be associated with lower vitamin D levels, it could be the potential implications for dietary recommendations.

A physiologically relevant role for NO stored in vascular smooth muscle cells: A novel theory of vascular NO signaling

S-nitrosothiols (SNO), dinitrosyl iron complexes (DNIC), and nitroglycerine (NTG) dilate vessels via activation of soluble guanylyl cyclase (sGC) in vascular smooth muscle cells. Although these compounds are often considered to be nitric oxide (NO) donors, attempts to ascribe their vasodilatory activity to NO-donating properties have failed. Even more puzzling, many of these compounds have vasodilatory potency comparable to or even greater than that of NO itself, despite low membrane permeability. This raises the question: How do these NO adducts activate cytosolic sGC when their NO moiety is still outside the cell? In this review, we classify these compounds as ‘nitrodilators’, defined by their potent NO-mimetic vasoactivities despite not releasing requisite amounts of free NO. We propose that nitrodilators activate sGC via a preformed nitrodilator-activated NO store (NANOS) found within the vascular smooth muscle cell. We reinterpret vascular NO handling in the framework of this NANOS paradigm, and describe the knowledge gaps and perspectives of this novel model.

Light-induced nitric oxide release in the skin beyond UVA and blue light: Red & near-infrared wavelengths

Nitric oxide (NO) is omnipresent in the body and synthesized by 3 isoenzymes (nNOS, eNOS and iNOS), all detected in human skin. NO can be stored in a pool of compounds readily converted to NO following skin irradiation by UVR and blue light. This non-enzymatic (without NOS involvement) photolytic reaction mobilizes cutaneous stores of NO derivatives to the bloodstream, lowering blood pressure. However, with the likelihood of skin deleterious effects caused by UVR/blue light, safer wavelengths in the red/near-infrared (NIR) spectrum are becoming potential contenders to release cutaneous NO, possibly via NOS temperature-dependent effects. The use of red/NIR light to mobilize NO stores from the body's largest organ (the skin) is auspicious. This review focuses on UVR, blue, red, and NIR spectra and their capacity to release NO in human skin. PubMed and Google Scholar were used as article databases to find relevant publications related to this particular field.

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.

Incidence of myocardial infarction and associated mortality varies by latitude and season: findings from a Swedish Registry Study

BACKGROUND

We investigated whether the incidence of death following myocardial infarction (MI) varied by season and latitude in the Swedish population.

METHODS

We studied deaths following MI from January 1987 to December 2009, using the Swedish National Cause of Death Register. County of residence was used to determine latitude and population density. An extension of Poisson regression was used to study the relationship between risk of death following MI with age, latitude, time (from 1987), population density and calendar days.

RESULTS

Over the study period, there was a secular decrease in the incidence of MI-related death. In men, MI-related death incidence increased by 1.3% [95% confidence interval (CI) = 1.1-1.5] per degree of latitude (northwards). In women, MI-related death incidence increased by 0.6% (95% CI = 0.4-0.9) per degree of latitude. There was seasonal variation in the risk of MI-related death with peak values in the late winter and a nadir in the summer months in both the north and the south of Sweden. Findings were similar with incident MI as the outcome.

CONCLUSIONS

The incidence of MI-related death varied markedly by season and latitude in Sweden, with summer months and more southerly latitude associated with lower rates than winter months and more northerly latitude.

Green Tea Catechin Association with Ultraviolet Radiation-Induced Erythema: A Systematic Review and Meta-Analysis

Catechins are a part of the chemical family of flavonoids, a naturally occurring antioxidant, and a secondary metabolite in certain plants. Green tea catechins are well recognized for their essential anti-inflammatory, photo-protective, antioxidant, and chemo-preventive functions. Ultraviolet radiation is a principal cause of damage to the skin. Studies observed that regular intake of green tea catechins increased the minimal dose of radiation required to induce erythema. The objectives of this systematic review and meta-analysis are to determine the effectiveness of green tea catechins in cutaneous erythema and elucidate whether green tea catechin consumption protects against erythema (sunburn) inflammation. A comprehensive literature search was conducted to identify the relevant studies. Two researchers carried out independent screening, data extraction, and quality assessment according to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). The pooled effect of green tea catechins on protection against erythema was assessed using approaches fixed-effects or random-effects model to quantify the effectiveness of green tea catechins in the erythema dose-response. Studies not be included in meta-analyses were summarized narratively. Six randomized controlled studies of enrolled studies regularly administrated green tea catechins orally for 6 to 12 weeks involving healthy volunteers comprising a total of 100 participants were included in the analysis. The results revealed green tea catechins have favorable protection against erythema inflammation even at increased minimal erythema dose (MED) of ultraviolet radiation. Meta-analysis results confirm oral supplementation of green tea catechins is highly effective at low-intensity ultraviolet radiation-induced erythema response (MED range; 1.25-1.30) compared to placebo, showing a significant pooling difference (p = 0.002) in erythema index (SMD: -0.35; 95% CI, -0.57 to -0.13; I² = 4%, p = 0.40) in the random-effects model. The pro-inflammatory signaling pathways through oral supplementation with green tea catechins are an attractive strategy for photo-protection in healthy human subjects and could represent a complementary approach to topical sunscreens. Therefore, studies that involved green tea catechin in topical applications to human subjects were also evaluated separately, and their meta-analysis is presented as a reference. The evidence indicates that regular green tea catechin supplementation is associated with protection against UV-induced damage due to erythema inflammation.

Second-trimester maternal serum vitamin D and pregnancy outcome: The Western Australian Raine cohort study

AIMS

To assess the effect of maternal serum 25(OH)-vitamin D levels during the second trimester of pregnancy on the risk for gestational diabetes (GDM), pregnancy and infantile outcomes.

METHODS

This study is based on the Western Australian Pregnancy Cohort (Raine) study. Maternal serum 25(OH)-vitamin D concentrations of 890 pregnant women were evaluated at 18 weeks pregnancy and grouped into serum Vitamin D quartiles (>30, 30-49, 50-74 and >75 nmol/L).

RESULTS

Participants with de-seasonalized 25 (OH)-vitamin D levels <30 nmol/L were more likely to develop GDM, but not after controlling for ethnicity. Women with high body mass index (BMI) >30 were at a greater risk of developing GDM. Additionally, women with GDM were at a greater risk of primary caesarean delivery. Maternal serum levels of 25(OH)-vitamin D were positively associated with birth weight, body length and head circumference of the neonate.

CONCLUSION

Low maternal serum levels of 25(OH)-vitamin D are associated with GDM gestational diabetes, and race/ethnicity may modify this relationship. High pre-gestational BMI may predict GDM risk. GDM in pregnancy may increase the risk for delivery by caesarean section. Maternal 25(OH)-vitamin D is associated with anthropometric measures of the neonate.

CACNA1C rs1006737 SNP increases the risk of essential hypertension in both Chinese Han and ethnic Russian people of Northeast Asia

Voltage-gated Ca2+ channels play a key role in the regulation of arterial tone and blood pressure. The aim of this study was to determine whether the association of calcium voltage-gated channel subunit alpha1 C (CACNA1C) rs1006737 with essential hypertension (EH) exists in both Chinese Han and ethnic Russian populations of Northeast Asia. We used a case-control study of 2 ethnic groups in the same latitude geographical area to investigate the association between the susceptibility of EH and rs1006737 polymorphism. A total of 1512 EH patients and 1690 controls in Chinese Han people (Heilongjiang Provence, China), 250 EH patients, and 250 controls in ethnic Russian people (Chita, Russia), participated in this study. All participants were genotyped using the TaqMan SNP genotyping assay (Agena Company). Baseline characteristics and the minor allele frequencies of rs1006737 vary substantially among common Chinese Han and ethnic Russian people. Allele A was found to be a risk factor for EH in Chinese Han [(odds ratio) OR 1.705, (confidence interval) 95% CI: 1.332-2.182, P < .001] and ethnic Russian (OR 1.437; 95% CI: 1.110-1.860, P = .006). The GA genotype was significantly associated with an increased risk of hypertension (OR 1.538, 95% CI: 1.188-1.991, P = .001) for Chinese Han people, and the AA genotype (OR 2.412, 95% CI: 1.348-4.318, P = .003) for ethnic Russian people. The results of this study indicate that the A allele of the variant rs1006737 in the CACNA1C gene may be a useful genetic marker for EH risk prediction in Chinese Han and ethnic Russian populations.

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.

Do extreme summers increase blood vitamin D (25-hydroxyvitamin D) levels?

Climate change is expected to increase the frequency of extreme weather events, such as extended heat waves and droughts in the northern hemisphere. Besides affecting ecosystems worldwide, these changes in climate patterns will also affect the environmental health of human populations. While the medical community is mostly concerned with the negative impact of climate change, there might also be some beneficial effects. In this study we used laboratory data from a large university clinic in Germany (n = 13 406), to test for any detectable impact of two extreme summers on Vitamin-D [25(OH)D] plasma concentrations over a six year period (2014-2019). For the two years with extreme summers (2018 and 2019) the 25(OH)D plasma concentrations were significantly higher than in the previous four years (p < 0.001). A time series analysis (autoregressive term, AR, φ = 0.84, with an AR of one indicating a persistent effect) showed that 25(OH)D concentrations rise by 0.04 nmol/l (95% CI: 0.04-0.05 nmol/l) per hour of sunshine. The incidence of vitamin D deficiency was generally high (60% for 2014-2017) but dropped by 10% in 2018 and 2019. As such, the summers of 2018 and 2019, which are among the hottest and driest in Germany since the start of modern climate recordings, had a measurable positive effect on 25(OH)D plasma levels of the examined population. Given that 25(OH)D deficiency is widespread in higher latitudes, this implies that while mostly considered negative, climate change might also confer some health benefits with regard to vitamin D related medical conditions.

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.

Safe, mild ultraviolet-B exposure: An essential human requirement for vitamin D and other vital bodily parameter adequacy: A review

The enigma of skin sunburning, skin ageing and skin cancer and essential vitamin D production both resulting from solar ultraviolet‐B (280‐315 nm) (UVB) exposure has long puzzled photobiologists. Advice to patients by non‐photobiological clinicians is now often to sunbathe to acquire vitamin D adequacy. However, modern work shows only mild UVB exposure is needed to maintain satisfactory levels, which have been demonstrated as very similar in summer and winter from about 25° to 70° north. Even very careful high protection factor 15 sunscreen use does not prevent adequate production, although it is slightly reduced, such that obsessive use of very protective screens of 50 + might. Dark skin pigmentation too usually at most minimally impairs production. However, confinement indoors and widespread clothing cover can, but oral supplementation overcomes any such deficiency. Thus, vitamin D adequacy needs just mild regular UVB skin exposure well under sunburning levels, unlikely to cause significant skin damage. This suggests mild UVB exposure may also be needed for other bodily requirements, which is indeed so. Thus, it also prevents the development of contact dermatitis and polymorphic light eruption through suppressing adaptive immunity. It also prevents the occurrence of multiple skin infections resulting from this suppression through stimulating innate immunity and cutaneous bacterial defensin production. Finally, blood pressure is reduced through low‐dose UVB‐induced production of the vasodilator nitric oxide (though UVA, 315‐400 nm, is more efficient). Thus, mild UVB exposure is important for several aspects of internal health, whereas high‐dose exposure is extremely detrimental to cutaneous health.

Sunlight and health: shifting the focus from vitamin D3 to photobiomodulation by red and near-infrared light

Both sun exposure and serum vitamin D levels have been associated with lower risks of all-cause mortality and chronic age-related diseases, e.g., cancer, diabetes and cardiovascular disease, in epidemiological studies. These associations have mainly been ascribed to beneficial effects of vitamin D. However, a vast body of randomized controlled trials (RCTs) and Mendelian randomization studies have failed to confirm any major health benefits from vitamin D supplementation. In this review, we present tentative evidence showing that red and near-infrared light, both being present in sunlight, could explain the associations between sunlight exposure and better health status. Body irradiation with red and near-infrared light, usually termed as photobiomodulation (PBM), has demonstrated beneficial effects in animal models of chronic diseases. Beyond this, preliminary evidence from RCTs suggest potential clinical benefit from PBM for chronic diseases. PBM is currently being investigated in many pre-registered clinical trials, results of which will eventually clarify the role of red and near-infrared light in the prevention and treatment of common age-related chronic diseases.

Both cardiovascular and cerebrovascular events are decreased following long-term narrowband ultraviolet B phototherapy in patients with vitiligo: a propensity score matching analysis

BACKGROUND

Systemic effects of long-term narrowband ultraviolet B (NB-UVB) phototherapy have not been well studied in vitiligo patients. An 11-year nationwide population-based retrospective cohort study was conducted using the Korean National Health Insurance claims database (2007-2017).

OBJECTIVES

To investigate the effects of long-term NB-UVB phototherapy on the risk of cardiovascular and cerebrovascular events in vitiligo patients.

METHODS

This study included vitiligo patients with ≥100 phototherapy sessions (phototherapy group, n = 3229) and <3 phototherapy sessions (no phototherapy group, n = 9687), in which covariables with age, sex, insurance type and comorbidities such as diabetes, hypertension and hyperlipidemia were matched by 1 : 3 propensity score matching. The outcomes of interest were cardiovascular (ischaemic heart disease and myocardial infarction) and cerebrovascular events (cerebrovascular infraction and haemorrhage). Cox proportional hazards models were used to assess the associations between NB-UVB phototherapy and each event.

RESULTS

The risk of cardiovascular or cerebrovascular events was significantly decreased in the phototherapy group compared with the no phototherapy group [hazard ratio (HR) 0.637, 95% confidence interval (CI) 0.523-0.776]. Subgroup analysis revealed that the risk of cardiovascular (HR: 0.682, 95% CI: 0.495-0.940) and cerebrovascular events (HR: 0.601, 95% CI: 0.470-0.769) were significantly lower in the phototherapy group than the no phototherapy group, respectively.

CONCLUSIONS

Our findings suggest that long-term NB-UVB phototherapy could decrease the risk of cardiovascular and cerebrovascular events in patients with vitiligo.

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.

Insufficient Sun Exposure Has Become a Real Public Health Problem

This article aims to alert the medical community and public health authorities to accumulating evidence on health benefits from sun exposure, which suggests that insufficient sun exposure is a significant public health problem. Studies in the past decade indicate that insufficient sun exposure may be responsible for 340,000 deaths in the United States and 480,000 deaths in Europe per year, and an increased incidence of breast cancer, colorectal cancer, hypertension, cardiovascular disease, metabolic syndrome, multiple sclerosis, Alzheimer's disease, autism, asthma, type 1 diabetes and myopia. Vitamin D has long been considered the principal mediator of beneficial effects of sun exposure. However, oral vitamin D supplementation has not been convincingly shown to prevent the above conditions; thus, serum 25(OH)D as an indicator of vitamin D status may be a proxy for and not a mediator of beneficial effects of sun exposure. New candidate mechanisms include the release of nitric oxide from the skin and direct effects of ultraviolet radiation (UVR) on peripheral blood cells. Collectively, this evidence indicates it would be wise for people living outside the tropics to ensure they expose their skin sufficiently to the sun. To minimize the harms of excessive sun exposure, great care must be taken to avoid sunburn, and sun exposure during high ambient UVR seasons should be obtained incrementally at not more than 5-30 min a day (depending on skin type and UV index), in season-appropriate clothing and with eyes closed or protected by sunglasses that filter UVR.

Does Incident Solar Ultraviolet Radiation Lower Blood Pressure?

Background Hypertension remains a leading global cause for premature death and disease. Most treatment guidelines emphasize the importance of risk factors, but not all are known, modifiable, or easily avoided. Population blood pressure correlates with latitude and is lower in summer than winter. Seasonal variations in sunlight exposure account for these differences, with temperature believed to be the main contributor. Recent research indicates that UV light enhances nitric oxide availability by mobilizing storage forms in the skin, suggesting incident solar UV radiation may lower blood pressure. We tested this hypothesis by exploring the association between environmental UV exposure and systolic blood pressure (SBP) in a large cohort of chronic hemodialysis patients in whom SBP is determined regularly. Methods and Results We studied 342 457 patients (36% black, 64% white) at 2178 US dialysis centers over 3 years. Incident UV radiation and temperature data for each clinic location were retrieved from the National Oceanic and Atmospheric Administration database. Linear mixed effects models with adjustment for ambient temperature, sex/age, body mass index, serum Na+/K+ and other covariates were fitted to each location and combined estimates of associations calculated using the DerSimonian and Laird procedure. Pre-dialysis SBP varied by season and was ≈4 mm Hg higher in black patients. Temperature, UVA and UVB were all linearly and inversely associated with SBP. This relationship remained statistically significant after correcting for temperature. Conclusions In hemodialysis patients, in addition to environmental temperature, incident solar UV radiation is associated with lower SBP. This raises the possibility that insufficient sunlight is a new risk factor for hypertension, perhaps even in the general population.

Public Health Implications of Solar UV Exposure during Extreme Cold and Hot Weather Episodes in 2018 in Chilton, South East England

Consideration of the implications of solar UV exposure on public health during extreme temperature events is important due to their increasing frequency as a result of climate change. In this paper public health impacts of solar UV exposure, both positive and negative, during extreme hot and cold weather in England in 2018 were assessed by analysing environmental variations in UV and temperature. Consideration was given to people’s likely behaviour, the current alert system and public health advice. During a period of severe cold weather in February-March 2018 UV daily doses were around 25–50% lower than the long-term average (1991–2017); however, this would not impact on sunburn risk or the benefit of vitamin D production. In spring 2018 unseasonably high temperatures coincided with high UV daily doses (40–75% above long-term average) on significant days: the London Marathon (22 April) and UK May Day Bank Holiday weekend, which includes a public holiday on the Monday (5–7 May). People were likely to have intermittent excess solar UV exposure on unacclimatised skin, causing sunburn and potentially increasing the risk of skin cancers. No alerts were raised for these events since they occurred outside the alerting period. During a heat-wave in summer 2018 the environmental availability of UV was high—on average of 25% above the long-term average. The public health implications are complex and highly dependent on behaviour and sociodemographic variables such as skin colour. For all three periods Pearson’s correlation analysis showed a statistically significant (p<0.05) positive correlation between maximum daily temperature and erythema-effective UV daily dose. Public health advice may be improved by taking account of both temperature and UV and their implications for behaviour. A health impact-based alert system would be of benefit throughout the year, particularly in spring and summer.

Redox Regulation of the Microcirculation

The microcirculation maintains tissue homeostasis through local regulation of blood flow and oxygen delivery. Perturbations in microvascular function are characteristic of several diseases and may be early indicators of pathological changes in the cardiovascular system and in parenchymal tissue function. These changes are often mediated by various reactive oxygen species and linked to disruptions in pathways such as vasodilation or angiogenesis. This overview compiles recent advances relating to redox regulation of the microcirculation by adopting both cellular and functional perspectives. Findings from a variety of vascular beds and models are integrated to describe common effects of different reactive species on microvascular function. Gaps in understanding and areas for further research are outlined. © 2020 American Physiological Society. Compr Physiol 10:229-260, 2020.

Atmospheric fronts as minor cardiovascular risk factors, a new approach to preventive cardiology

BACKGROUND

Cardiovascular diseases are the number one cause of death globally and represent 31% of all global deaths. The aim of our study was to determine the influence of front effects on acute cardiovascular diseases (ACVDs).

METHODS

We obtained all ACVD admissions in a Central-European region, Hungary, Budapest. A time-series analysis was applied to 6499 morbidity cases during a five-year period (2009-2013). Poisson-regression model was used and adjusted for air temperature, pressure, humidity, wind velocity, their interactions and seasonality to assess the association of fronts and ACVDs.

RESULTS

There is a positive significant association between ACVDs and a cold front effect lagged by one day (p=0.018) with a relative risk (RR) of 1.095 [95% CI (1.021,1.181)]. Our findings show that among patient subgroups with major cardiovascular risk factors (hypertension, diabetes, hyperlipidemia, history of CVDs) the patterns are similar, but occluded fronts also have a significant effect.

CONCLUSION

Atmospheric fronts could play an important role in the pathogenesis of ACVDs. Our findings might help to provide a better understanding about fronts as minor cardiovascular risk factors and to organize medical prevention more effectively. Our research project may become a basis of a new field of preventive cardiovascular medicine in the future.

Complex effects of atmospheric parameters on acute cardiovascular diseases and major cardiovascular risk factors: data from the CardiometeorologySM study

Several studies have examined the cardiovascular effects of atmospheric parameters as separate factors; however, few have investigated atmospheric parameters’ joint effects. We aim to explore the joint effects of atmospheric parameters on acute cardiovascular diseases (ACVDs) and on major cardiovascular risk factors (CRFs). We correlated all ACVD admissions with major CRFs and local atmospheric conditions during a 5-year study period. A seasonal variation was detected in a higher incidence rate during cold atmospheric conditions. There were significant incidence relative ratios, including: 1.140 (95% CI [1.020, 1.283]) for daily temperature change (≥5 °C); 0.991 (95% CI [0.988, 0.994]) for average daily temperature; and 1.290 (95% CI [1.090, 1.599]) for the interaction of daily temperature change (≥5 °C) with humidity change (≥40%). We observed a significant association between the atmospheric parameters’ joint effects and hyperlipidaemia, diabetes, and previous ACVDs. Patients with diabetes had the highest significant incidence relative ratio at 2.429 (95% CI [1.088, 5.424]) for humidity-temperature interactions. Thus, the atmospheric parameters’ joint effects play an important role as minor CRFs. These unfavourable atmospheric situations are predicted to increase the number of ACVDs mainly. Our study may help to organize prevention strategies more effectively and to reduce cardiovascular risks.

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.

Homeostasis in Topical Photoprotection: Getting the Spectral Balance Right

The solar radiation range has harmful and beneficial effects. Sunscreens, which selectively block specific spectral regions, may potentially interfere with skin homeostasis. For instance, the ultraviolet (UV) B waveband produces erythema and DNA damage; simultaneously, it induces pre-vitamin D₃ synthesis. UVA1 and visible light can both induce pigmentation in skin phototypes IV–VI, and act in synergy to induce erythema and persistent pigment darkening. In contrast, UVA may contribute to blood pressure control and cardioprotection by inducing release of nitric oxide from intracutaneous photolabile nitric oxide derivatives. Finally, infrared A radiation alters the collagen equilibrium of the dermal extracellular matrix but is involved in the regulation of body temperature and in nitric oxide release, with a potential beneficial impact on blood pressure regulation. Ideally, photoprotection should thus be performed with a neutral density filter, mitigating all radiation ranges homogeneously, to maintain solar spectrum homeostasis. Natural compounds such as mycosporine-like amino acids are promising natural UV radiation-filtering compounds for an improved homeostasis with our environment. Lastly, we should not forget individual characteristics and behavior, as homeostasis differs according to individual phototypes and skin exposure behaviors.

A time for everything and everything in its time - exploring the mechanisms underlying seasonality of COPD exacerbations

Across Europe, COPD affects 23 million people leading to annual health care costs of ~€25.1 billion. This burden is particularly severe during winter months in association with the peak incidence of exacerbation events. Seasonal variation in the health status of patients with COPD places additional and often critical pressure on already strained health care resources. COPD exacerbations are characterized by worsening day-to-day symptoms of an individual and often triggered by respiratory infections, but the process by which this occurs in a seasonal fashion is likely to be multifactorial. In this review, we discuss recent population studies that highlight the impact of seasonality in COPD and review the proposed biological mechanisms underlying this. An appraisal of the role of the host susceptibility and response, environmental triggers and the biology of respiratory pathogens is detailed. The impact of each aspect is considered, and an integrated model of the context for the whole individual and society in general is explored.

The health benefits of UV radiation exposure through vitamin D production or non-vitamin D pathways. Blood pressure and cardiovascular disease

The detrimental effects of ultraviolet radiation are well known. Skin cancer, photo-aging, and induction or exacerbation of photosensitive dermatoses have been the focus of most photobiological research since 1928 when Findlay confirmed the carcinogenicity of ultraviolet radiation using a murine model of skin cancer. The epidemiological, mechanistic and clinical trial data have enabled the classification by the International Agency for Research on Cancer of ultraviolet radiation as a Group 1 ('sufficient evidence') carcinogen for human skin. Public health advice in most developed countries with a pale-skinned population following this has advocated limiting exposure to sunlight through use of clothing, sunblock and behavioural alterations. Despite this plethora of data, one striking omission is evidence that ultraviolet radiation shortens life, and as I will lay out in this chapter, epidemiological and now mechanistic data suggest that UV may have significant benefits on health and in particular cardiovascular health.

Exposure amount and timing of solar irradiation during pregnancy and the risk of sensitization in children

BACKGROUND

Solar irradiation affects sensitization to aeroallergens and the prevalence of allergic diseases. Little is known, however, about how the time and amount of solar irradiation during pregnancy affects such risks in children. We aimed to find out how solar irradiation during pregnancy affects sensitization to aero-allergens and the prevalence of allergic diseases in children.

METHODS

This population-based cross-sectional study involved 7301 aged 6 years and aged 12 years children. Maternal exposure to solar irradiation during pregnancy was evaluated using data from weather stations closest to each child's birthplace. Monthly average solar irradiation during the second and third trimesters was calculated with rank by quartiles. Risks of allergic sensitization and allergic disease were estimated.

RESULTS

Relative to the first (lowest) quartile, the adjusted odds ratio (aOR) for allergic sensitization in the fourth (highest) quartile was lowest within solar irradiation during pregnancy months 5-6 (aOR = 0.823, 95% CI 0.720-0.942, p < 0.05). During months 9-10, the aOR for allergic sensitization for the fourth was higher than the first quartile of solar irradiation (aOR = 1.167, 95% CI 1.022-1.333, p < 0.05). Similar results were observed when solar irradiation was analyzed as a continuous variable during months 5 (aOR = 0.975, 95% CI 0.962-0.989, p < 0.001) and month 9 (aOR = 1.018, 95% CI 1.004-1.031, p = 0.003). Increased solar irradiation during months 7-8 increased the risk of asthma (aOR = 1.309, 95% CI 1.024-1.674, p = 0.032).

CONCLUSIONS

Maternal exposure to solar irradiation during the second trimester of pregnancy associated with reduced aeroallergen sensitization, whereas solar irradiation during the third trimester was related to increased sensitization to aeroallergens.

Geographical Variation in Dementia Mortality in Italy, New Zealand, and Chile: The Impact of Latitude, Vitamin D, and Air Pollution

BACKGROUND

Dementia risk is reported as being higher in the north compared to the south, which may be related to vitamin D deficiency. If this were the case, an opposite gradient of risk would be observed in the southern hemisphere, but this has not been investigated previously.

METHODS

We calculated standardised mortality ratios (SMRs) for deaths in 2012 where dementia (Alzheimer's disease, vascular or unspecified dementia) was recorded as the underlying cause for 20 regions in Italy, 20 District Health Board areas in New Zealand and 29 Health Service areas in Chile.

RESULTS

Dementia SMRs were higher in northern than central or southern Italy. The inverse pattern was seen in women in New Zealand, with rates higher on South Island than North Island. However, dementia risk was raised in eight regions in the north and centre of Chile in both men and women.

CONCLUSIONS

Geographical variation plays a key role in dementia risk, but patterns vary in men and women. In the northern hemisphere, dementia mortality is higher in the north, but the pattern in the southern hemisphere is more complex.

Ultraviolet Radiation-Induced Production of Nitric Oxide:A multi-cell and multi-donor analysis

Increasing evidence regarding positive effects of exposure to sunlight has led to suggestions that current advice may be overly weighted in favour of avoidance. UV-A has been reported to lower blood pressure, possibly through nitric oxide (NO) production in skin. Here, we set out to investigate effects of UV-A and solar-simulated radiation on the potential source of dermal NO, the effective doses and wavelengths, the responsiveness of different human skin cells, the magnitude of inter-individual differences and the potential influence of age. We utilised isogenic keratinocytes, microvascular endothelial cells, melanocytes and fibroblasts isolated from 36 human skins ranging from neonates to 86 years old. We show that keratinocytes and microvascular endothelial cells show greatest NO release following biologically relevant doses of UV-A. This was consistent across multiple neonatal donors and the effect is maintained in adult keratinocytes. Our observations are consistent with a bi-phasic mechanism by which UV-A can trigger vasodilatory effects. Analyses of NO-production spectra adds further evidence that nitrites in skin cells are the source of UV-mediated NO release. These potentially positive effects of ultraviolet radiation lend support for objective assessment of environmental influence on human health and the idea of “healthy sun exposure”.

Out-of-hospital cardiac arrest attributable to sunshine: a nationwide, retrospective, observational study

Aims

To investigate the population attributable risk of out-of-hospital cardiac arrest (OHCA) from non-optimal sunshine duration and the relative contribution of daily sunshine hours.

Methods and Results

National registry data of all cases of OHCA occurred between 2005 and 2014 in the 47 Japanese prefectures were obtained. We examined the relationship between daily duration of sunshine and OHCA risk for each prefecture in Japan using a Poisson regression model combined with a distributed lag non-linear model, adjusting for confounding factors. The estimated associations for each prefecture were pooled at the nationwide level using a multivariate random-effects meta-analysis. A total of 658 742 cases of OHCA of presumed cardiac origin met our inclusion criteria. The minimum morbidity sunshine duration varied from the 21st percentile in Okayama to the 99th percentile in Hokkaido, Gifu, and Hyogo. Overall, 5.78% [95% empirical confidence interval (eCI): 3.57-7.16] of the OHCA cases were attributable to daily sunshine duration. The attributable fraction for short sunshine duration (below the minimum morbidity sunshine duration) was 4.18% (95% eCI: 2.64-5.38), whereas that for long sunshine duration (above the minimum morbidity sunshine duration) was 1.59% (95% eCI: 0.81-2.21).

Conclusions

Daily sunshine duration was responsible for OHCA burden, and a greater number of OHCA cases occurred in patients who were only exposed to sunshine for short periods of time each day. Our findings suggest that public health efforts to reduce OHCA burden should take sunshine level into account.

Chitosan nanoparticles for nitric oxide delivery in human skin

The use of nanoparticle-based transdermal delivery systems is a promising approach to efficiently carry and deliver therapeutic agents for dermal and systemic administration. Nitric oxide (NO) is a key molecule that plays important roles in human skin such as the control of skin homeostasis, skin defense, control of dermal blood flow, and wound healing. In addition, human skin contains stores of NO derivatives that can be mobilized and release free NO upon UV irradiation with beneficial cardiovascular effects, for instance the control of blood pressure. In this work, the NO donor precursor glutathione (GSH) was encapsulated (encapsulation efficiency of 99.60%) into ultra-small chitosan nanoparticles (CS NPs) (hydrodynamic size of 30.65 ± 11.90 nm). GSH-CS NPs have a core-shell structure, as revealed by atomic force microscopy and X-ray photoelectron spectroscopy, in which GSH is protected in the nanoparticle core. Nitrosation of GSH by nitrous acid led to the formation of the NO donor S-nitrosogluthathione (GSNO) into CS NPs. The GSNO release from the CS NPs followed a Fickian diffusion described by the Higuchi mathematical model. Topical application of GSNO-CS NPs in intact human skin significantly increased the levels of NO and its derivatives in the epidermis, as assayed by confocal microscopy, and this effect was further enhanced by skin irradiation with UV light. Therefore, NO-releasing CS NPs are suitable materials for transdermal NO delivery to local and/or systemic therapies.

Skin Cancer: Epidemiology, Disease Burden, Pathophysiology, Diagnosis, and Therapeutic Approaches

Skin cancer, including both melanoma and non-melanoma, is the most common type of malignancy in the Caucasian population. Firstly, we review the evidence for the observed increase in the incidence of skin cancer over recent decades, and investigate whether this is a true increase or an artefact of greater screening and over-diagnosis. Prevention strategies are also discussed. Secondly, we discuss the complexities and challenges encountered when diagnosing and developing treatment strategies for skin cancer. Key case studies are presented that highlight the practic challenges of choosing the most appropriate treatment for patients with skin cancer. Thirdly, we consider the potential risks and benefits of increased sun exposure. However, this is discussed in terms of the possibility that the avoidance of sun exposure in order to reduce the risk of skin cancer may be less important than the reduction in all-cause mortality as a result of the potential benefits of increased exposure to the sun. Finally, we consider common questions on human papillomavirus infection.

Avoidance of sun exposure as a risk factor for major causes of death: a competing risk analysis of the Melanoma in Southern Sweden cohort

OBJECTIVE

Women with active sunlight exposure habits experience a lower mortality rate than women who avoid sun exposure; however, they are at an increased risk of skin cancer. We aimed to explore the differences in main causes of death according to sun exposure.

METHODS

We assessed the differences in sun exposure as a risk factor for all-cause mortality in a competing risk scenario for 29 518 Swedish women in a prospective 20-year follow-up of the Melanoma in Southern Sweden (MISS) cohort. Women were recruited from 1990 to 1992 (aged 25-64 years at the start of the study). We obtained detailed information at baseline on sun exposure habits and potential confounders. The data were analysed using modern survival statistics.

RESULTS

Women with active sun exposure habits were mainly at a lower risk of cardiovascular disease (CVD) and noncancer/non-CVD death as compared to those who avoided sun exposure. As a result of their increased survival, the relative contribution of cancer death increased in these women. Nonsmokers who avoided sun exposure had a life expectancy similar to smokers in the highest sun exposure group, indicating that avoidance of sun exposure is a risk factor for death of a similar magnitude as smoking. Compared to the highest sun exposure group, life expectancy of avoiders of sun exposure was reduced by 0.6-2.1 years.

CONCLUSION

The longer life expectancy amongst women with active sun exposure habits was related to a decrease in CVD and noncancer/non-CVD mortality, causing the relative contribution of death due to cancer to increase.

Is outdoor recreational activity an independent predictor of cardiovascular disease mortality - NHANES III?

BACKGROUND AND AIMS

To investigate if frequency of outdoor recreational activity (ORA) predicts cardiovascular disease (CVD) mortality, independent of serum 25(OH)D concentration.

METHODS AND RESULTS

Baseline data on ORA and serum 25(OH)D, collected from 11,746 participants aged 30-90 years in the Third National Health and Nutrition Examination Survey during 1988-1994, were linked to the National Death Index for assessment of CVD deaths from baseline through December 2006. CVD mortality as a primary cause of death was assessed during a mean follow up of 12.9 (SD, 4.2) years. There were 1519 CVD deaths during follow up. A strong positive association was observed between frequency of ORA in the last month and serum 25(OH)D (p < 0.001). Compared to participants who did no ORA in the last month, the hazard ratio (HR) of CVD mortality was 0.72 (95% confidence interval 0.58-0.90) for those doing ORA 1-4 times, 0.64 (0.47-0.89) for 5-12 times, 0.70 (0.56-0.89) for 13-30 times and 0.63 (0.47-0.84) for ≥30 times (p-trend < 0.001), in a Cox proportional hazards regression model which included 25(OH)D and CVD risk factors. Serum 25(OH)D was inversely associated with CVD mortality (p-trend, 0.01) in this same model.

CONCLUSIONS

An inverse association between ORA and CVD mortality was observed independent of 25(OH)D. The underlying mechanism for this association may not involve 25(OH)D hence, further studies are warranted to confirm and investigate the underlying mechanism.

The risks and benefits of sun exposure 2016

Public health authorities in the United States are recommending that men, women and children reduce their exposure to sunlight, based on concerns that this exposure will promote skin cancer. On the other hand, data show that increasing numbers of Americans suffer from vitamin D deficiencies and serious health problems caused by insufficient sun exposure. The body of science concerning the benefits of moderate sun exposure is growing rapidly, and is causing a different perception of sun/UV as it relates to human health. Melanoma and its relationship to sun exposure and sunburn is not adequately addressed in most of the scientific literature. Reports of favorable health outcomes related to adequate serum 25(OH)D concentration or vitamin D supplementation have been inappropriately merged, so that benefits of sun exposure other than production of vitamin D are not adequately described. This review of recent studies and their analyses consider the risks and benefits of sun exposure which indicate that insufficient sun exposure is an emerging public health problem. This review considers the studies that have shown a wide range health benefits from sun/UV exposure. These benefits include among others various types of cancer, cardiovascular disease, Alzheimer disease/dementia, myopia and macular degeneration, diabetes and multiple sclerosis. The message of sun avoidance must be changed to acceptance of non-burning sun exposure sufficient to achieve serum 25(OH)D concentration of 30 ng/mL or higher in the sunny season and the general benefits of UV exposure beyond those of vitamin D.