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

Circadian rhythmicity and human health

Our modern lifestyle involves irregular eating habits and extended periods spent indoors under artificial lighting. This lifestyle contrasts with the body's circadian rhythms and likely contributes to an increase of chronic diseases worldwide. This special issue on the circadian rhythm contains articles that deepen our understanding of the biological rhythmicity associated with health and disease. Research articles include studies on the effects of light therapy in patients with myocardial infarction and 24-hour ambulatory blood pressure monitoring in Japanese women and in patients receiving one of five anti-hypertensive drugs. Review articles cover the roles of micro-RNAs in colorectal cancer, the influence of light, electromagnetic fields and water on biological rhythms, and the effects of eating patterns on metabolic diseases. These studies and review articles highlight the importance of maintaining circadian rhythms and provide practical tips to improve human health.

Joint association of vitamin D deficiency and sleep disorders with cardiovascular mortality: a prospective cohort study

Purpose

Vitamin D deficiency and sleep disorders may independently contribute to increased mortality, but the combined effects of these two factors on mortality remain unknown. This study aimed to investigate both the separate and joint effects of vitamin D deficiency and sleep disorders on cardiovascular disease mortality, as well as all-cause mortality and cancer mortality.

Methods

We analyzed data from 24,566 adults in the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2018. Sleep disorders were assessed using self-report questionnaires, and vitamin D levels were measured through serum total 25-hydroxyvitamin D [25(OH)D]. Cox proportional hazards models were employed to evaluate the associations between separate and joint effects of vitamin D deficiency and sleep disorders with mortality outcomes.

Results

Over a median follow-up of 9.08 years, we included a total of 24,566 individuals, in this study. Among them, 2,776 cases were all-cause deaths, 858 were cardiovascular disease deaths, and 644 were cancer deaths. We found that Vitamin D deficiency was independently associated with an increased risk of all-cause mortality, while sleep disorders were similarly associated with a higher risk of all-cause mortality. Notably, participants with both vitamin D deficiency and sleep disorders exhibited a significantly higher risk of all-cause mortality (HR, 2.31; 95% CI: 1.36-3.91) and cardiovascular mortality (HR, 2.39; 95% CI, 1.03-5.58) compared to those with only one or neither risk factor, even after adjusting for potential confounders.

Conclusion

Our study highlights that the combination of vitamin D deficiency and sleep disorders was associated with an increased risk of all-cause and cardiovascular mortality in adults. These findings might help to refine dietary and lifestyle intervention strategies for this population.

Photosensitizing Drugs and Risk of Skin Cancer in Women-A Prospective Population-Based Study

BACKGROUND

Several widely used drugs have photosensitizing properties, and much research has been conducted to find associations between their use and the risk of developing cutaneous malignant melanoma (cM), basal cell carcinoma (BCC) or cutaneous squamous cell carcinoma (cSCC), often with conflicting results.

OBJECTIVE

To assess whether the use of commonly prescribed photosensitizing drugs increases skin cancer risk.

METHODS

Analyses were performed using a large cohort of women, with prospectively collected information on phenotypic traits and sun exposure. Comprehensive information on pharmaceutical treatments and skin cancer occurrence was obtained through national registries. Drugs with photosensitizing properties were grouped according to the Anatomical Therapeutic Chemical system in nine groups, and associations between the use of such drugs were investigated using multivariable Cox regression analysis. The number of retrieved daily doses was analyzed to test the dose-response relationship.

RESULTS

Hormone replacement therapy significantly increased the risk of BCC (hazard ratio [HR] 1.24; 95% confidence interval [CI]: 1.11-1.39), cSCC (HR 1.23; 95% CI: 1.03-1.47) and cM (HR 1.31; 95% CI: 1.01-1.69), with estrogen driving this risk. There was a trend of increased risk of BCC and cM with higher doses of estrogen treatment. Subgroup analysis among those using diuretics showed that loop diuretics were associated with increased cSCC risk (HR 1.6; 95% CI: 1.3-2.0), including a positive association between risk and dose. Furthermore, increased risks of BCC (HR 1.25; 95% CI: 1.09-1.44) and cM (HR 1.41; 95% CI: 1.03-1.93) were associated with thiazide use. NSAIDs showed a possible curvilinear association to BCC and cSCC.

CONCLUSIONS

Estrogen treatment increased the risk of all investigated skin cancers. Among those using diuretics, loop diuretics increased the risk of cSCC, and thiazide use increased the risk of BCC. We suggest that physicians should advise female patients prescribed estrogen, thiazides, or loop diuretics to limit their sun exposure.

Illuminating the Connection: Cutaneous Vitamin D3 Synthesis and Its Role in Skin Cancer Prevention

Sunlight exposure plays an important role in human health, impacting processes such as mood, blood pressure regulation, and vitamin D3 production. Solar ultraviolet B radiation initiates vitamin D3 synthesis in the skin, which is subsequently metabolized into its biologically active form. UVB exposure plays a key role in enabling vitamin D3 synthesis, but it can also contribute to skin carcinogenesis, creating a complex interplay between its beneficial and harmful effects. Vitamin D deficiency, affecting over half the global population, is linked to a range of chronic diseases, including cancers, cardiovascular conditions, and autoimmune disorders. Simultaneously, excessive solar UVB exposure increases the risk of non-melanoma and melanoma skin cancers through mechanisms involving DNA damage and oxidative stress. This review examines the dual role of UVB radiation in health and disease, focusing on the mechanisms of cutaneous vitamin D3 synthesis, the epidemiology of skin cancer, and the protective roles of vitamin D3's photoproducts and its active metabolite, 1,25-dihydroxyvitamin D3. Understanding these interconnections is critical for developing strategies that balance adequate sun-induced vitamin D3 production with skin cancer prevention.

Mothers Practices and Factors Affecting Sunlight Exposure of Their Infants in Adami Tulu Jido Kombolcha District, East Shoa Zone, Oromia Region, Ethiopia, 2022: A Community Based Cross-Sectional Study

Background. Vitamin D deficiency (VDD) is a global health concern affecting people of all ages. The Ethiopian guidelines recommend sun exposure for neonates starting from 2 weeks old, with 15 to 20 minutes per day. However, evidence suggests that the implementation of this recommendation is inconsistent. Most studies conducted in Ethiopia regarding infant sunlight exposure have been limited to health facilities and towns. Objective. this study aimed to assess mothers' practice, and factors affecting the sunlight exposure of their infants in Adami Tulu Jido Kombolcha district, East Shoa Zone, Oromia Region, Ethiopia, 2022. Method. A community based cross-sectional study design was conducted among 575 mothers with their infant's from March 11 to 25, 2022. A lottery method sampling technique was employed to select local administrative units and systematic random sampling employed to select study participants. Practices and knowledge were assessed by categorizing mothers based on their responses to practice and knowledge questions, respectively. Mothers who scored above the mean value of 4.5 were classified as having good practice, while those who scored 6.9 or below on the knowledge questions were classified as having poor knowledge. Data were collected through face-to-face interviews using both semi-structured and structured questionnaires. The data were then entered into EPI Data version 3.1 and exported to SPSS version 25 for analysis. The association between variables was analyzed using bivariate and multivariable binary logistic regression and level of significant determined with adjusted odd ratio at 95% CI and P-value less than <.05. Result. All 575 mothers were interviewed and responded 100%. Out of 567 mothers, 55.2% had good practice of infant sunlight exposure. Lack of advice at health facility (AOR = 3.05, 95% CI: 1.08, 8.60), absence of postnatal care follow up (AOR = 2.38, 95% CI: 1.15, 4.94) and poor knowledge about sunlight exposure (AOR = 1.70, 95% CI: 1.15, 2.50) were factors associated with practice of infant sunlight exposure. Conclusions. In this study, more than half of the mothers had good practice of infants' sunlight exposure. This study highlights the importance of improving maternal knowledge and healthcare practices related to infant sunlight exposure. Key factors affecting these practices include lack of advice at health facilities, absence of postnatal care follow-up, and poor maternal knowledge. To address these issues, healthcare providers, local health offices, and mass media should focus on educational programs and strengthening advice during health visits. Future research should use validated tools and mixed-method approaches to better understand the social and cultural factors at play. Establishing national guidelines and studying infant serum vitamin D levels can further enhance community awareness and promote the benefits of sunlight exposure.

Does Omega-3 supplementation increase profuse postpartum hemorrhage? A hospital-based register study

INTRODUCTION

Although Omega-3 is thought to have anticoagulative properties, the potential untoward effects of Omega-3 during pregnancy have not been investigated. No previous studies have been made to specifically assess its effect on postpartum hemorrhage (PPH). Our aim was to determine if an association exists between Omega-3 intake during pregnancy and profuse PPH or massive PPH.

MATERIAL AND METHODS

Data on all deliveries that occurred at Karolinska University Hospital during the years 2007-2011 (n = 41 139) was collected from the medical record of Obstetrix, maternal health and delivery chart system. Women with reported Omega-3 use in early pregnancy were considered exposed and all other as unexposed. Bivariate and adjusted multivariate analysis was performed on main outcomes.

RESULTS

Omega-3 use was associated with 25% increased odds of PPH (adjusted odds ratio (aOR) 1.25, 95% confidence interval [CI] (1.06-1.47)) and a more than doubled odds of massive PPH (aOR 2.36, 95% CI 1.26-4.44). In addition, there was a minor increase in the amount of blood loss. Although few, women on low-dose discontinued terminated at 36th week showed no significant association to blood loss measurements.

CONCLUSIONS

Our observational findings showed 25% higher odds of PPH and two times higher odds of massive PPH in women who reported using Omega-3 in early pregnancy. Our findings give some support to advocate discontinued use of Omega-3 in late pregnancy.

Higher ultraviolet light exposure is associated with lower mortality: An analysis of data from the UK biobank cohort study

We aimed to examine associations between ultraviolet (UV) exposure and mortality among older adults in the United Kingdom (UK). We used data from UK Biobank participants with two UV exposures, validated with measured vitamin D levels: solarium use and annual average residential shortwave radiation. Associations between the UV exposures, all-cause and cause-specific mortality were examined as adjusted hazard ratios. The UV exposures were inversely associated with all-cause, cardiovascular disease (CVD) and cancer mortality. Solarium users were also at a lower risk of non-CVD/non-cancer mortality. The benefits of UV exposure may outweigh the risks in low-sunlight countries.

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.

Reliability and validity of the Chinese version of the sunlight exposure questionnaire

Objective

This study aimed to translate and validate the reliability and validity of the Chinese version of the Philippines Sunlight Exposure Questionnaire.

Methods

A total of 392 Chinese individuals aged at least 18 years, residing in various cities in Sichuan province for at least 1 year, were recruited. The reliability of the Chinese version of the questionnaire was measured through internal consistency, split-half reliability, and retest reliability, while validity was determined using the content validity index and the structure validity index.

Results

The Chinese version of the Sunlight Exposure Questionnaire, which includes 19 items covering 5 factors, demonstrated McDonald's omega coefficient of 0.788. The split-half reliability of the questionnaire was 0.823, and the retest reliability was 0.940. The content validity index (S-CVI) was 0.952. The five-factor structure, supported by eigenvalues, explained 66.2% of the total variance. Confirmatory factor analysis indicated favorable model fit.

Results

The chi-square value degrees of freedom ratio (χ2/df) = 1.852, the goodness-of-fit index (GFI) = 0.938, the normed fit index (NFI) = 0.922, the incremental fit index (IFI) = 0.962, the comparative fit index (CFI) = 0.962, the Tucker-Lewis index (TLI) = 0.952, and root mean square error of approximation (RMSEA) = 0.047. The indicators of the fit of the model were within reasonable bounds.

Conclusion

The Chinese version of the Sunlight Exposure Questionnaire shows validity and good reliability for assessing sun exposure among adults in a Chinese cultural context.

Self-Reported Outdoor Light Exposure Time and Incident Heart Failure

BACKGROUND

A healthy lifestyle is an important factor for preventing heart failure. However, the association between outdoor light exposure time and heart failure is still unknown. The aim of this study was to examine the association between outdoor light exposure time and the incidence of heart failure.

METHODS AND RESULTS

This cohort study included participants from the UK Biobank recruited from 2006 to 2010 who were 40 to 70 years of age and free of heart failure at baseline. The mean follow-up time was 12.61 years. The outdoor light exposure time was self-reported at baseline. A restricted cubic spline was performed to examine the potential nonlinear relationship between outdoor light exposure and the incidence of heart failure. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and 95% CIs. During a mean follow-up of 12.61 years, 13 789 participants were first diagnosed with heart failure. There was a nonlinear (J-shaped) trend between outdoor light time and heart failure risk. Cox proportional hazard regression models showed that, compared with participants who received an average of 1.0 to 2.5 hours of outdoor light per day, those with <1.0 hours or >2.5 hours had a higher risk of heart failure after the model was adjusted for age and sex (<1.0 hours: HR, 1.27 [95% CI, 1.18-1.36]; >2.5 hours: HR, 1.11 [95% CI, 1.07-1.15]). These associations were still significant in the fully adjusted models (<1.0 hours: HR, 1.10 [95% CI, 1.03-1.18]; >2.5 hours: HR, 1.07 [95% CI, 1.03-1.11]).

CONCLUSIONS

We found a J-shaped association between outdoor light exposure time and the risk of incident heart failure, suggesting that moderate exposure to outdoor light may be a prevention strategy for heart failure.

Nationwide Geospatial Analysis to Identify Variations in Primary Cardiovascular Risk in Ethiopia

BACKGROUND

Cardiovascular disease (CVD) varies across regions due to socioeconomic, cultural, lifestyle, healthcare access, and environmental factors.

OBJECTIVE

To find geographical variations in 10-year primary CVD risk and assess the impact of contextual factors on CVD risk.

METHOD

Data from 2658 Ethiopians aged 40 to 69 years with no previous CVD who participated in a nationally representative World Health Organization (WHO) STEPS survey in 2015 were included in the analysis. The mean 10-year CVD risk for 450 enumeration areas (EA) was used to identify spatial autocorrelation (using Global Moran's I) and CVD hot spots (using getas-Ord Gi*). Geographically Weighted Regression (GWR) analysis quantified the relationship between mean 10-year CVD risk and climate-related factors across areas.

RESULT

The spatial autocorrelation analysis identified significant spatial variation in the 10-year CVD risk at the EA level, with a global Moran's I value of 0.016. Statistically significant hot spot areas with 10-year CVD risk were identified in Addis Ababa (the capital), Benishangul Gumuz, SNNPR (Southern Nations, Nationalities, and Peoples' Region), Amhara, Afar, Oromia, and Hareri regions. In a multivariable GWR analysis, average water vapor pressure was a statistically significant explanatory variable for the geographical variations in 10-year CVD risk.

CONCLUSION

Hot spot areas for 10-year CVD risk were identified across numerous country regions rather than concentrated in a specific region. Alongside these hot spot areas, regions with a higher annual water vapor pressure (humidity) were identified as geographical targets for CVD prevention.

Skin epidermal keratinocyte p53 induces food uptake upon UV exposure

Introduction

The first cells affected by UVB exposure are epidermal keratinocytes, and p53, the genome guardian, is activated in these cells when skin is exposed to UVB. UVB exposure induces appetite, but it remains unclear whether p53 in epidermal keratinocytes plays a role in this appetite stimulation.

Results

Here we found that food intake was increased following chronic daily UVB exposure in a manner that depends on p53 expression in epidermal keratinocytes. p53 conditional knockout in epidermal keratinocytes reduced food intake in mice upon UVB exposure.

Methods

To investigate the effects of p53 activation following UVB exposure, mice behavior was assessed using the staircase, open-field, elevated-plus maze, and conditioned-place preference tests. In addition to effects on appetite, loss of p53 resulted in anxiety-related behaviors with no effect on activity level.

Discussion

Since skin p53 induces production of β-endorphin, our data suggest that UVB-mediated activation of p53 results in an increase in β-endorphin levels which in turn influences appetite. Our study positions UVB as a central environmental factor in systemic behavior and has implications for the treatment of eating and anxiety-related disorders.

Seasonal AMH variability implies a positive effect of UV exposure on the deterioration of ovarian follicles

Anti-Müllerian hormone (AMH) is produced exclusively by granulosa cells of ovarian follicles and is an indicator of ovarian reserve which declines with age. Seasonality in AMH levels have been reported to be correlated with variations in Vitamin D levels, which is dependent on sunlight exposure. However, the effects of age and its association with solar radiation intensity with respect to AMH was never studied before. In this study, we investigated the relationship between AMH levels with season and with solar radiation intensity in a cohort of 2235 women aged 19-40 years undergoing hormonal work-up over a four-year period. Our findings revealed that among women aged 20-29 years, there was no significant association between AMH levels and either season or solar radiation intensity. However, for women aged 30-40 years, a seasonal pattern was observed, with higher AMH levels during spring and autumn months characterized by moderate solar radiation intensity. Women in their declining ovarian reserve age were found to be more sensitive to the effects of moderate solar radiation. Moderate solar radiation exposure positively impacted AMH levels, whereas low and high intensity exposure had a negative effect. Our findings indicate that age and solar radiation intensity must be considered when assessing AMH levels and provide valuable insights into the intricate relationship between AMH, seasonality, and UVB exposure in the context of reproductive health.

Association between sun-protective behaviors and hypertension: a cross-sectional study from National Health and Nutrition Examination Survey 2009 to 2014

BACKGROUND

In previous studies, sun-protective behaviors increased cardiovascular incidence. Our present article is to further analyze the potential relationship between sun-protective behaviors (staying in the shade, wearing long-sleeved clothing, and applying sunscreen) and hypertension.

METHOD

The present cross-sectional study evaluated 8,613 participants (aged 20-60 years) from the National Health and Nutrition Examination Survey (NHANES) obtained between 2009 and 2014. We performed multiple logistic regression analysis to examine the relationship between sun-protective behaviors and hypertension. Subgroup analysis was then performed. Multiple linear regression analysis was utilized to examine the relationship of sun-protective behaviors and each sun-protective behavior with systolic and diastolic blood pressure, stratified by sex and race.

RESULTS

A total of 8,613 participants (weighted n = 127,909,475) were applied in our study, including 1,694 hypertensive subjects. Our study demonstrated that sun-protective behaviors of the 2-3 category were associated with increased risk of hypertension, but not with higher systolic and diastolic blood pressure. In subgroup analysis, men, Mexican American, and 25 < BMI ≤ 30 who reported sun-protective behaviors (2-3) were prone to hypertension. Multiple linear regression models showed that non-Hispanic white men with sun-protective behaviors (2-3) were positively associated with systolic and diastolic blood pressure. The association between other-Hispanic men with frequent wearing long-sleeved clothing and diastolic blood pressure was positively correlated.

CONCLUSION

Sun-protective behaviors of the 2-3 category could increase the incidence of hypertension, but not increase systolic and diastolic blood pressure. We only found that non-Hispanic white men who reported sun-protective behaviors (2-3) were positively associated with systolic and diastolic blood pressure. These findings suggested that excessive sun-protective behaviors should be avoided.

Can active sun exposure decrease the risk of giant cell arteritis and polymyalgia rheumatica in women?

Objectives

To study if active sun exposure among women affects the risk of developing GCA or PMR in a prospective cohort study with restricted latitudinal variability.

Methods

We linked the response to questions relating to sun exposure from the Melanoma Inquiry in Southern Sweden (MISS) prospective cohort study in women to the risk of developing GCA or PMR. Healthcare data were gathered from the Skåne Healthcare Register (SHR), covering all public healthcare consultations. The direct effect of active sun exposure on the risk of developing GCA or PMR was assessed using Cox proportional hazards models adjusted for covariates based on a directed acyclic graph.

Results

A total of 14 574 women were included in the study; 601 women were diagnosed with GCA or PMR (144 and 457, respectively) during the follow-up time. Women with moderate or high sun exposure were not less likely to develop GCA or PMR compared with women that indicated they avoided sun exposure [hazard ratio (HR) 1.2 (CI 0.9, 1.6) and 1.3 (0.9, 1.9), respectively] when adjusted for diabetes, hyperlipidaemia, hypertension, smoking, obesity and stratified by age. Similar patterns were observed when studying only GCA [HR 1.2 (CI 0.7, 2.3) and 1.3 (0.7, 2.6)] and only PMR [HR 1.3 (CI 0.9, 1.8) and 1.4 (0.9, 2.0)].

Conclusion

Active sun exposure did not affect the risk of developing GCA or PMR in women in a cohort with restricted latitudinal variability.

Is there a relation between stillbirth and low levels of vitamin D in the population? A bi-national follow-up study of vitamin D fortification

BACKGROUND

Stillbirth has been associated with low plasma vitamin D. Both Sweden and Finland have a high proportion of low plasma vitamin D levels (< 50 nmol/L). We aimed to assess the odds of stillbirth in relation to changes in national vitamin D fortification.

METHODS

We surveyed all pregnancies in Finland between 1994 and 2021 (n = 1,569,739) and Sweden (n = 2,800,730) with live or stillbirth registered in the Medical Birth Registries. The mean incidences before and after changes in the vitamin D food fortification programs in Finland (2003 and 2009) and Sweden (2018) were compared with cross-tabulation with 95% confidence intervals (CI).

RESULTS

In Finland, the stillbirth rate declined from ~ 4.1/1000 prior to 2003, to 3.4/1000 between 2004 and 2009 (odds ratio [OR] 0.87, 95% CI 0.81-0.93), and to 2.8/1000 after 2010 (OR 0.84, 95% CI 0.78-0.91). In Sweden, the stillbirth rate decreased from 3.9/1000 between 2008 and 2017 to 3.2/1000 after 2018 (OR 0.83, 95% CI 0.78-0.89). When the level of the dose-dependent difference in Finland in a large sample with correct temporal associations decreased, it remained steady in Sweden, and vice versa, indicating that the effect may be due to vitamin D. These are observational findings that may not be causal.

CONCLUSION

Each increment of vitamin D fortification was associated with a 15% drop in stillbirths on a national level. If true, and if fortification reaches the entire population, it may represent a milestone in preventing stillbirths and reducing health inequalities.

Sun Exposure and Intima-Media Thickness in the Mexican Teachers' Cohort Study

Objective: To determine whether long-term sun exposure has a protective role in subclinical cardiovascular disease in adult Mexican women. Materials and Methods: We conducted a cross-sectional analysis of a sample of women from the Mexican Teachers' Cohort (MTC) study. Sun exposure was assessed in the MTC 2008 baseline questionnaire, in which women were asked about their sun-related behavior. Vascular neurologists measured carotid intima-media thickness (IMT) using standard techniques. Multivariate linear regression models were used to estimate the difference in mean IMT and 95% confidence intervals (95% CIs), according to categories of sun exposure and multivariate logistic regression models were used to estimate the odds ratio (OR) and 95% CIs for carotid atherosclerosis. Results: The mean age of participants was 49.6 ± 5.5 years, the mean IMT was 0.678 ± 0.097 mm, and the mean accumulated hours of weekly sun exposure were 2.9 ± 1.9. Prevalence of carotid atherosclerosis was 20.9%. Compared with women in the lowest quartile of sun exposure, women in the highest quartile had lower mean IMT, but this was not significant in the multivariable adjusted analysis. (Adjusted mean % difference: -0.8; 95% CI: -2.3 to 0.8). The multivariate adjusted ORs of carotid atherosclerosis were 0.54 (95% CI: 0.24-1.18) for women who were exposed 9 hours. For women who denied regular sunscreen use, those in the higher exposure category (9 hours) had lower mean IMT compared with those in the lower category (multivariable-adjusted mean % difference = -2.67; 95% CI: -6.9 to -1.5). Conclusions: We observed that cumulative sun exposure was inversely associated with IMT and subclinical carotid atherosclerosis. If these findings are further replicated and seen for other cardiovascular outcomes, sun exposure could be an easy, affordable strategy to lower overall cardiovascular risk.

Solar Ultraviolet Radiation Temporal Variability Analysis from 2-Year of Continuous Observation in an Amazonian City of Brazil

Solar ultraviolet radiation (UVR) is a highly energetic component of the solar spectrum that needs to be monitored because of the effects on human health and on the ecosystems. In Brazil, few cities monitor UVR, especially in the Amazon region which is particularly poor in observation. This work is the first to address the short-term (2-year) time variability of UVR in Santarém (2°25′ S, 54°44′ W, 51 m) using ground-based measurements. The irradiance in the wavelength range of 250–400 nm was investigated on different time scales. Furthermore, to understand how the UVR varies without the influence of clouds, the hours corresponding to the clear sky condition were analyzed as well as the hours in all sky conditions. Regarding the averages, there is a slight variation over the year. In all sky and clear sky conditions, the dry season had a higher average than the rainy season, despite the slight difference. Also, both in all-sky and clear-sky conditions the maximums occurred around local solar noon, and reached a maximum of 87 in the dry season under the clear sky condition. Further understanding of the radiative effects of the clouds in UVR time variability is considered essential for future research. This study can serve as a reference for UVR levels in this region where no other ground-based UVR measurements are made.

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.

Food-seeking behavior is triggered by skin ultraviolet exposure in males

Sexual dimorphisms are responsible for profound metabolic differences in health and behavior. Whether males and females react differently to environmental cues, such as solar ultraviolet (UV) exposure, is unknown. Here we show that solar exposure induces food-seeking behavior, food intake, and food-seeking behavior and food intake in men, but not in women, through epidemiological evidence of approximately 3,000 individuals throughout the year. In mice, UVB exposure leads to increased food-seeking behavior, food intake and weight gain, with a sexual dimorphism towards males. In both mice and human males, increased appetite is correlated with elevated levels of circulating ghrelin. Specifically, UVB irradiation leads to p53 transcriptional activation of ghrelin in skin adipocytes, while a conditional p53-knockout in mice abolishes UVB-induced ghrelin expression and food-seeking behavior. In females, estrogen interferes with the p53-chromatin interaction on the ghrelin promoter, thus blocking ghrelin and food-seeking behavior in response to UVB exposure. These results identify the skin as a major mediator of energy homeostasis and may lead to therapeutic opportunities for sex-based treatments of endocrine-related diseases.

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.

Mortality of Enlisted Men Who Served on Nuclear-Powered Submarines in the United States Navy

OBJECTIVE

To describe the long-term mortality experience of a cohort of enlisted men who served on nuclear-powered submarines in the United States Navy and breathed recirculated filtered air for extended periods of time.

METHODS

In this historical cohort study we estimated standardized mortality ratios (SMRs) and used within-cohort Poisson regression analyses to address healthy worker biases.

RESULTS

Three thousand two hundred sixty three deaths occurred among 85,498 men during 1,926,875 person-years of follow-up from 1969 to 1995. SMRs were reduced for most cause-of-death categories, prostate cancer had a twofold elevation. In within-cohort comparisons, prostate cancer mortality did not increase with duration of submarine service, but ischemic heart disease mortality increased 26% per 5 years of submarine service.

CONCLUSIONS

Long periods of submarine service do not increase mortality in most cause-of-death categories. Increased mortality from ischemic heart disease likely reflects the effects of tobacco smoke.

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.

Photoaging factors in patients from two healthcare centers in Colombia

BACKGROUND

Exposure to solar radiation has been documented as a direct cause of skin changes associated with aging, and its effects have been categorized as photoaging.

OBJECTIVE

To explore the clinical characteristics of photoaging and its relationship with external predisposing factors in a Colombian urban and rural population.

METHODS

We included 350 patients on outpatient consultation at Clínica Chía in Zipaquirá (rural) and Hospital Universitario Barrios Unidos in Bogotá (urban) in an observational, cross-sectional study with an analytical component included, between 2018 and 2019. A survey was conducted and photographs were taken. A group of experts determined the degree of photoaging.

RESULTS

The majority of respondents worked in closed environments (n = 222). The main sociodemographic variable associated was age (p = 0.000). Factors such as smoking, alcohol consumption, use of sunscreen, exercising, and sun exposure were also associated with scale progression (p < 0.05). Exercising (odds ratio (OR) 0.6, 95% confidence interval (CI) 0.3-0.9) and being from Bogotá (OR 0.6, 95% CI 0.2-0.9) appeared as protective factors. Smoking (OR 1.6, 95% CI 1.0-2.6) was defined as a risk factor.

CONCLUSIONS

Changes related to photoaging and photocarcinogenesis are associated with sun exposure. However, there are environmental factors, such as smoking, alcohol consumption, sedentary lifestyle, woman's age at first delivery, and number of children, among others, that affect the degree of photoaging. It is necessary to explore these relationships in higher evidence level studies to define their causality.

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.

Religion, Age, Education, Lifestyle, and Health: Structural Equation Modeling

This study aimed to analyze the moderating effect of religion between sociodemographic variables, lifestyle, and self-referred physical and mental health. Cross-sectional study with non-randomized sample of 392 participants. The Eight Natural Remedies Questionnaire was used to assess lifestyle. Religion was found to be positive predictor between age, education and lifestyle, better physical and mental health. Being an Adventist positively influenced the lifestyle (r = 0.680; p < 0.05) and consequently physical (r = 0.222) and mental health (r = 0.220). Belonging to a religion that emphasizes a healthy lifestyle is a contributing factor toward better lifestyle, physical and mental health.

Understanding sunscreen and photoprotection misinformation on parenting blogs: A mixed-method study

BACKGROUND/OBJECTIVES

Sun exposure during childhood is a modifiable risk factor for skin cancer. Social media (including parenting blogs) represent promising platforms for understanding misinformation about pediatric photoprotection. This study's objective was to qualitatively and quantitatively evaluate the digital social context of parenting blogs that shape parents' decisions about children's photoprotection.

METHODS

Mixed-method analysis was conducted of the 25 most popular parenting blogs in the USA, including 56 blog posts addressing photoprotection and 2661 comments. An inductive method was used to code and identify key themes associated with blog post categorization as sunscreen-encouraging, -discouraging, and -ambivalent. The qualitative analysis program NVivo was used to calculate descriptive statistics for comment codes based on co-occurrence with blog post category.

RESULTS

Sunscreen-discouraging posts addressed natural remedies, sunscreen recipes, and vitamin D. Sunscreen-encouraging posts focused on skin cancer and protective clothing. Sunscreen-ambivalent posts were associated with scientific studies. Sunscreen-discouraging posts received more comments (mean 124) than encouraging (31) or ambivalent posts (8). Discouraging (65%) and ambivalent posts (75%) cited scientific literature more often than encouraging posts (14%). Comments were twice as likely to discourage photoprotection as to encourage it (1340 vs 447 comments).

CONCLUSIONS

Parenting blogs are a substantial resource of both information and misinformation on pediatric photoprotection. However, misinformation receives substantially more engagement. The themes revealed in this study may help physicians and public health officials in developing interventions to target misinformation around pediatric photoprotection.

Oxidative Stress in Ischemic Heart Disease

One of the novel interesting topics in the study of cardiovascular disease is the role of the oxidation system, since inflammation and oxidative stress are known to lead to cardiovascular diseases, their progression and complications. During decades of research, many complex interactions between agents of oxidative stress, oxidation, and antioxidant systems have been elucidated, and numerous important pathophysiological links to na number of disorders and diseases have been established. This review article will present the most relevant knowledge linking oxidative stress to vascular dysfunction and disease. The review will focus on the role of oxidative stress in endotheleial dysfunction, atherosclerosis, and other pathogenetic processes and mechanisms that contribute to the development of ischemic heart disease.

Investigating the Potential for Ultraviolet Light to Modulate Morbidity and Mortality From COVID-19: A Narrative Review and Update

During the COVID-19 (coronavirus disease of 2019) pandemic, researchers have been seeking low-cost and accessible means of providing protection from its harms, particularly for at-risk individuals such as those with cardiovascular disease, diabetes and obesity. One possible way is via safe sun exposure, and/or dietary supplementation with induced beneficial mediators (e.g., vitamin D). In this narrative review, we provide rationale and updated evidence on the potential benefits and harms of sun exposure and ultraviolet (UV) light that may impact COVID-19. We review recent studies that provide new evidence for any benefits (or otherwise) of UV light, sun exposure, and the induced mediators, vitamin D and nitric oxide, and their potential to modulate morbidity and mortality induced by infection with SARS-CoV-2 (severe acute respiratory disease coronavirus-2). We identified substantial interest in this research area, with many commentaries and reviews already published; however, most of these have focused on vitamin D, with less consideration of UV light (or sun exposure) or other mediators such as nitric oxide. Data collected to-date suggest that ambient levels of both UVA and UVB may be beneficial for reducing severity or mortality due to COVID-19, with some inconsistent findings. Currently unresolved are the nature of the associations between blood 25-hydroxyvitamin D and COVID-19 measures, with more prospective data needed that better consider lifestyle factors, such as physical activity and personal sun exposure levels. Another short-coming has been a lack of measurement of sun exposure, and its potential to influence COVID-19 outcomes. We also discuss possible mechanisms by which sun exposure, UV light and induced mediators could affect COVID-19 morbidity and mortality, by focusing on likely effects on viral pathogenesis, immunity and inflammation, and potential cardiometabolic protective mechanisms. Finally, we explore potential issues including the impacts of exposure to high dose UV radiation on COVID-19 and vaccination, and effective and safe doses for vitamin D supplementation.

On the Relationship Between Sun Exposure and All-Cause Mortality

Increasing sun exposure is related to lower prevalence of death in cardiovascular disease (CVD), type 2 diabetes, and other noncancer non-CVD. In this chapter we aim to make a short update on the knowledge regarding sun exposure and all-cause mortality. Data support the hypothesis that low sun exposure habits are a major risk factor for all-cause mortality. Low sun exposure is related to an increased risk of death due to CVD and noncancer/non-CVD, and a minor reduction in risk of cancer. Active sun exposure habits have a dual effect; it increases the incidence of skin cancer, but also improves the prognosis in terms of all-cause mortality. In a low solar intensity region, we should carefully assess both risk and benefits of sun exposure in order to obtain balanced recommendations.

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.

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.

The Effect of Ultraviolet B Irradiation Compared with Oral Vitamin D Supplementation on the Well-being of Nursing Home Residents with Dementia: A Randomized Controlled Trial

There are indications that ultraviolet B (UVB) exposure has beneficial effects on well-being through mechanisms other than vitamin D synthesis alone. We conducted a randomized controlled multicenter trial to compare the effects of UVB light and vitamin D supplementation (VD) in terms of the well-being of nursing home residents with dementia. Participants were randomly assigned to the intervention group (UVB group, n = 41; half-body UVB irradiation, twice weekly over 6 months, with 1 standard erythema dose (SED)) or to the control group (VD group, n = 37; 5600 International units (IU) cholecalciferol supplementation once a week). The main outcome was well-being, measured by the Cohen-Mansfield Agitation Inventory (CMAI) and the Cornell scale for depression in dementia at 0, 3, and 6 months. Secondary outcomes were QUALIDEM quality of life domains and biochemical parameters of bone homeostasis. Intention-to-treat analysis with linear mixed modeling showed no significant between-group differences on agitation (p = 0.431) or depressive symptoms (p = 0.982). At six months, the UVB group showed less restless/tense behavior compared to the VD group (mean difference of the mean change scores 2.2, 95% CI 0.8 to 3.6; p = 0.003 for group x time interaction) and lower serum 25(OH)D3 concentration (estimated mean difference - 21.9, 95% CI −32.6 to −11.2; p = 0.003 for group difference). The exposure of nursing home residents with dementia to UVB light showed no positive benefits in terms of wellbeing. UVB treatment may have a positive effect on the restless/tense behavior characteristic of advanced dementia but more research is needed to confirm this finding.

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.

Women with fair phenotypes seem to confer a survival advantage in a low UV milieu. A nested matched case control study

BACKGROUND

Sun exposure in combination with skin pigmentation is the main determinant for vitamin D status. Human skin color seems to be adapted and optimized for regional sun ultraviolet (UV) intensity. However, we do not know if fair, UV-sensitive skin is a survival advantage in regions with low UV radiation.

METHODS

A population-based nested case-control study of 29,518 Caucasian women, ages 25 to 64 years from Southern Sweden who responded to a questionnaire regarding risk-factors for malignant melanoma in 1990 and followed for 25 years. For each fair woman, defined as having red hair or freckles (n = 11,993), a control was randomly selected from all non-fair women from within the cohort of similar age, smoking habits, education, marital status, income, and comorbidity, i.e., 11,993 pairs. The main outcome was the difference in all-cause mortality between fair and non-fair women in a low UV milieu, defined as living in Sweden and having low-to-moderate sun exposure habits. Secondary outcomes were mortality by sun exposure, and among those non-overweight.

RESULTS

In a low UV milieu, fair women were at a significantly lower all-cause mortality risk as compared to non-fair women (log rank test p = 0.04) with an 8% lower all-cause mortality rate (hazard ratio [HR] = 0.92, 95% CI 0.84‒1.0), including a 59% greater risk of dying from skin cancer among fair women (HR 1.59, 95% CI 1.26‒2.0). Thus, it seem that the beneficial health effect from low skin coloration outweigh the risk of skin cancer at high latitudes.

CONCLUSION

In a region with low UV milieu, evolution seems to improve all-cause survival by selecting a fair skin phenotype, i.e., comprising fair women with a survival advantage.

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.

Life Expectancy at Birth in Europe: An Econometric Approach Based on Random Forests Methodology

The objective of this work is to identify and classify the relative importance of several socioeconomic factors which explain life expectancy at birth in the European Union (EU) countries in the period 2008–2017, paying special attention to greenhouse gas emissions and public environmental expenditures. Methods: The Random Forests methodology was employed, which allows classification of the socioeconomic variables considered in the analysis according to their relative importance to explain health outcomes. Results: Per capita income, the educational level of the population, and the variable AREA (which reflects the subdivision of Europe into four relatively homogeneous areas), followed by the public expenditures on environmental and social protection, are the variables with the highest relevance in explaining life expectancy at birth in Europe over the perip.1 he peusto el correo e inciod 2008–2017. Conclusions: We have identified seven sectors as the main sources of greenhouse gas emissions: Electricity, gas, steam, and air conditioning supply; manufacturing; transportation and storage; agriculture, forestry, and fishing; construction; wholesale and retail trade, repair of motor vehicles and motorcycles; and mining and quarrying. Therefore, any public intervention related to environmental policy should be aimed at these economic sectors. Furthermore, it will be more effective to focus on public programs with higher relevance to the health status of the population, such as environmental and social protection expenditures.

The Paleolithic Nutrition Model in Relation to Ultraviolet Light and Vitamin D

The biology of every species has been optimized for life in the environment in which that species evolved. Humans originated in the tropics, and while some natural selection took place in response to behaviors and environments that decreased exposure to ultraviolet light, there has never been a species-wide biological accommodation. Paleolithic nutrition advocates argue that risk of disease is higher because modern diets differ from what was consumed by early humans. Early humans were the naked ape living in the tropics, exposed to high levels of ultraviolet light and vitamin D nutrition (serum 25-hydroxyvitamin D; 25(OH)D) averaging 115 nmol/L, as compared to today's population averages that are well below 70 nmol/L. Natural selection from an available gene pool cannot compensate fully to an environmental change away from the one within which the species originally evolved. Vitamin D nutrition remains a contentious area. The epidemiological evidence consistently relates lower 25(OH)D to higher disease risk. However, evidence from double-blind clinical trials looking at preventing new disease in healthy volunteers has been disappointing. But such negative trials have been the case for all nutrients except for folic acid which lowers risk of spina bifida. The Paleolithic nutrition model is based on fundamental biological concepts, but it has overlooked the environmental effects of ultraviolet light and vitamin D nutrition. This paper presents evolutionary and Paleolithic aspects of ultraviolet light and vitamin D with the aim to support pertinent research and, ultimately, public policy regarding nutrition and light exposure.

UVA and Seasonal Patterning of 56 370 Myocardial Infarctions Across Scotland, 2000-2011

Background Myocardial infarction exhibits seasonal patterning, with higher amplitude at increased latitude. Epidemiological evidence suggests that sunlight is protective against cardiovascular disease, independent of ambient temperature, but ultraviolet B-mediated vitamin D production has been discounted as causal. We aimed to determine whether ultraviolet A is associated with the seasonal patterning of myocardial infarction. Methods and Results Routine hospitalization data were used to determine monthly incidence of myocardial infarction in Scotland between 2000 and 2011. Small-area-level aggregated data were obtained on ambient temperature from the Meteorological Office and ultraviolet A and ultraviolet B irradiance from NASA satellites. Autoregressive distributed lag models were run for ultraviolet A and myocardial infarction, including adjustment for ambient temperature and ultraviolet B. Monthly incidence of myocardial infarction displayed winter peaks and summer troughs superimposed on the underlying trend, with a mean amplitude of 0.31 (95% CI: 0.21, 0.41) myocardial infarctions per 100 000 population per month. Ultraviolet A exposure was inversely associated with myocardial infarction independent of ambient temperature (coefficient, -0.05; 95% CI, -0.09, -0.01; P=0.015) and ultraviolet B UVB (coefficient, -0.05; 95% CI, -0.09, -0.02; P=0.004). Conclusions Further research is required to explore whether an ultraviolet-mediated mechanism different to vitamin D, such as nitric oxide-mediated vasodilatation, may play a causal role in the seasonal and geographical patterning of myocardial infarction.

Evaluation of In Vitro Solar Protection Factor (SPF), Antioxidant Activity, and Cell Viability of Mixed Vegetable Extracts from Dirmophandra mollis Benth, Ginkgo biloba L., Ruta graveolens L., and Vitis vinífera L

The aim of this study was to validate a HPLC method for the assay of flavonoids in extracts obtained from natural sources, i.e., from Dirmophandra mollis Benth, Ginkgo biloba L., Ruta graveolens L., and Vitis vinífera L. The potential sun protecting effect, antioxidant activity, and cell viability of the extracts were also determined. Individual extracts (obtained from each individual species) and a mixed extract (containing the four extracts) were analyzed by the validated HPLC method for the identification of flavonoids and quantification of rutin and quercetin. An in vitro cell viability study was carried out using the neutral red method. The in vitro sun protection factor was determined by spectral transmittance and in vitro antioxidant efficacy was evaluated against DPPH, ABTS, and AAPH radicals. The HPLC method used for the identification and quantification of flavonoids in extracts exhibited linearity, precision, accuracy, and robustness. Detection and quantification limits were, respectively, 2.881 ± 0.9 μg·mL^-1 and 0.864 ± 0.9 μg·mL^-1 for quercetin, and 30.09 ± 1 μg·mL^-1 and 9.027 ± 1.1 μg·mL^-1 for rutin. All extracts did not affect cell viability at the evaluated concentration range and exhibited a sun protection effect and antioxidant activity. Among the evaluated extracts, Ginkgo biloba L. and the mixed extract depicted the most expressive antioxidant activity. The mixed extract exhibited sunscreen protection against ultraviolet A (UVA) and ultraviolet B (UVB) and a critical wavelength of 372.7 ± 0.1. Our results translate the enhanced flavonoids' composition of the mixed extract, which may be a potential alternative over sunscreens and antioxidants in pharmaceutic/cosmetic formulations.

A Review of the Potential Benefits of Increasing Vitamin D Status in Mongolian Adults through Food Fortification and Vitamin D Supplementation

Serum 25-hydroxyvitamin D (25(OH)D) concentrations are low in Mongolia, averaging 22 ng/mL in summer and only 8 ng/mL in winter. Mongolians have high incidence and/or prevalence of several diseases linked to low 25(OH)D concentrations, including ischemic heart disease, malignant neoplasms, cirrhosis of the liver, ischemic stroke, lower respiratory tract infections, preterm birth complications, and diabetes mellitus. Fortifying regularly consumed foods such as flour, milk, and edible oils with vitamin D₃ could raise 25(OH)D concentrations by about 10 ng/mL. However, to achieve 25(OH)D concentrations of 30–40 ng/mL in adults, vitamin D intakes of 1000 to 4000 IU/day would be required, making personal supplement use necessary. On the basis of prospective observational studies and clinical trials of disease incidence or known mortality rates and adverse pregnancy and birth outcomes, raising mean serum 25(OH)D concentrations to 40 ng/mL would likely reduce incidence and mortality rates for those and other diseases, reduce the rate of adverse pregnancy and birth outcomes, and increase mean life expectancy by one year or more.

Sustainable effect of individualised sun protection advice on sun protection behaviour: a 10-year follow-up of a randomised controlled study in primary care

Background

In the light of increasing skin cancer incidences worldwide, preventive measures to promote sun protection in individuals with risky sun habits have continued relevance and importance.

Aim

To report the long-term effect of individualised sun protection advice given in primary health care (PHC), on sun habits and sun protection behaviour.

Design & setting

In 2005, 309 PHC patients were enrolled in a randomised controlled study performed in a Swedish PHC setting.

Method

At baseline, the study participants completed a Likert scale-based questionnaire, mapping sun habits, propensity to increase sun protection, and attitudes towards sun exposure, followed by randomisation into three intervention groups, all receiving individualised sun protection advice: in Group 1 (n = 116) by means of a letter, and in Group 2 (n = 97) and 3 (n = 96) communicated personally by a GP. In Group 3, participants also underwent a skin ultraviolet-sensitivity phototest, with adjusted sun protection advice based on the result. A repeated questionnaire was administered after 3 and 10 years.

Results

Statistically significant declines were observed in all groups for sun exposure mean scores over time. When using a cumulative score, according to the Sun Exposure and Protection Index (SEPI), significantly greater decrease in SEPI mean score was observed in Groups 2 and 3 (GP), compared to Group 1 (letter); P<0.01. The addition of a phototest did not enhance the effect of the intervention.

Conclusion

Individualised sun protection advice mediated verbally by the GP can lead to sustained improvement of sun protective behaviour.

Better prognostic determination and feature characterization of cutaneous melanoma through integrative genomic analysis

Melanoma is the most dangerous type of skin cancer and has highly heterogeneous features. Despite progress in melanoma classification, interpatient heterogeneity remains difficult to predict, especially in terms of long-term survival. Here, based on mRNA-seq, miRNA-seq and DNA methylation data from 447 cutaneous melanoma patients in the Cancer Genome Atlas, we performed integrative and single-dataset clustering analyses. A novel group of patients was identified, including 301 with better, 55 with poorer and 91 with intermediate prognoses. Immune genes were upregulated in the better prognostic group, and higher immune scores (representing a greater extent of immune cell infiltration into tumor tissues) were associated with better prognoses. Higher expression of 115 genes was determined to predict better outcomes. The better prognostic group also exhibited DNA hypomethylation, and immune pathways were enriched among the hypomethylated genes. Using exome-seq data from the same patients, we observed that the better prognostic group harbored the highest number of mutations. The mutational signature in the better prognostic group was associated with ultraviolet light exposure. These integrated investigations have potential therapeutic significance, as they clarify the molecular heterogeneity of cutaneous melanoma and enhance its classification.

Vitamin D and health in the Mediterranean countries

Vitamin D, traditionally well known for its role in maintaining optimal health through its contribution to calcium metabolism and skeletal health, has received increased attention over the past two decades, with considerable focus being placed on its nonskeletal benefits. This paper is a narrative review of the nonskeletal health benefits of vitamin D, of particular interest to inhabitants of Mediterranean countries, namely, autism, cancer, cardiovascular disease, chronic obstructive pulmonary disease, dental caries, diabetes mellitus, erectile dysfunction, hypertension, metabolic syndrome, respiratory tract infections, all-cause mortality, and pregnancy and birth outcomes, because of the relatively high incidence and/or prevalence of these disorders in this region. Currently, the best evidence is coming out of observational studies related to serum 25-hydroxyvitamin D [25(OH)D] concentrations. Vitamin D clinical trials have generally been poorly designed and conducted, usually being based on vitamin D dose rather than 25(OH)D concentration. The optimal 25(OH)D concentration is above 75 nmol/l (30 ng/ml), with even better health outcomes in the range of 100-150 nmol/l. Achieving these concentrations with vitamin D₃ supplements will require 1000-4000 IU/day of vitamin D₃. Sensible sun exposure should also be encouraged. Countries should also consider fortifying grain and dairy products with vitamin D₃.

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.