Synergistic and Non-synergistic Associations for Cigarette Smoking and Non-tobacco Risk Factors for Cardiovascular Disease Incidence in the Atherosclerosis Risk In Communities (ARIC) Study

Cross-Sectional Gene-Smoking Interaction Analysis in Relation to Subclinical Atherosclerosis-Results From the IMPROVE Study

BACKGROUND

Smoking is associated with carotid intima-media thickness (C-IMT). However, knowledge about how genetics may influence this association is limited. We aimed to perform nonhypothesis driven gene-smoking interaction analyses to identify potential genetic variants, among those included in immune and metabolic platforms, that may modify the effect of smoking on carotid intima-media thickness.

METHODS

We used baseline data from 1551 men and 1700 women, aged 55 to 79, included in a European multi-center study. Carotid intima-media thickness maximum, the maximum of values measured at different locations of the carotid tree, was dichotomized with cut point values ≥75, respectively. Genetic data were retrieved through use of the Illumina Cardio-Metabo- and Immuno- Chips. Gene-smoking interactions were evaluated through calculations of Synergy index (S). After adjustments for multiple testing, P values of <2.4×10-7 for S were considered significant. The models were adjusted for age, sex, education, physical activity, type of diet, and population stratification.

RESULTS

Our screening of 207 586 SNPs available for analysis, resulted in the identification of 47 significant gene-smoking synergistic interactions in relation to carotid intima-media thickness maximum. Among the significant SNPs, 28 were in protein coding genes, 2 in noncoding RNA and the remaining 17 in intergenic regions.

CONCLUSIONS

Through nonhypothesis-driven analyses of gene-smoking interactions, several significant results were observed. These may stimulate further research on the role of specific genes in the process that determines the effect of smoking habits on the development of carotid atherosclerosis.

Incidence of Coronary Artery Disease in King Abdulaziz University Hospital, Jeddah, Saudi Arabia, 2019–2020: A Retrospective Cohort Study

Background

Coronary artery disease (CAD) remains a significant cause of death and morbidity in people globally despite advances in treatment. Prevention of CAD risk factors is crucial to reducing its prevalence. We conducted this study to determine the incidence of CAD from 2019 to 2020 in King Abdulaziz University Hospital (KAUH), Jeddah, Kingdom of Saudi Arabia (KSA), and its major risk factors among this population.

Method

This retrospective study involved all patients diagnosed with CAD at KAUH in 2019 and 2020. We analyzed validated hospital data to determine the incidence of CAD and identify the risk factors among participants. The incidence of CAD was calculated based on the total number of patients admitted to KAUH by gender, age group, and nationality (Saudi/non-Saudi).

Result

The study included 1,364 patients with a mean age of 49 years. Most patients were men (n=1,050; 77%), with fewer women (n=314; 23%), and 71.2% were non-Saudi. The incidence of CAD in 2019 was 220.98 per 10,000, and the incidence in 2020 was 3,030.52 per 10,000. However, the incidence for 2020 was confounded by the coronavirus disease 2019 pandemic-related restrictions affecting hospital admissions. The most common diagnosis was acute transmural myocardial infarction, and patients aged <60 years had a significantly high incidence of hypertension, high total cholesterol levels, low low-density lipoprotein levels, and high triglyceride levels. Patients ≥60 years had a significantly high incidence of chronic kidney disease, low hemoglobin levels, history of ischemic heart disease, and intensive care unit or critical care unit admission.

Conclusion

The study demonstrated a significant rise in CAD incidence associated with advanced age and male sex. Further prevention and control of these risk factors would be essential to decrease the incidence of CAD. A national community-based prevention effort should be implemented to avoid the expected CAD epidemic in KSA.

The Impact of 51 Risk Factors on Life Expectancy in Canada: Findings from a New Risk Prediction Model Based on Data from the Global Burden of Disease Study

The aims of this study were (1) to develop a comprehensive risk-of-death and life expectancy (LE) model and (2) to provide data on the effects of multiple risk factors on LE. We used data for Canada from the Global Burden of Disease (GBD) Study. To create period life tables for males and females, we obtained age/sex-specific deaths rates for 270 diseases, population distributions for 51 risk factors, and relative risk functions for all disease-exposure pairs. We computed LE gains from eliminating each factor, LE values for different levels of exposure to each factor, and LE gains from simultaneous reductions in multiple risk factors at various ages. If all risk factors were eliminated, LE in Canada would increase by 6.26 years for males and 5.05 for females. The greatest benefit would come from eliminating smoking in males (2.45 years) and high blood pressure in females (1.42 years). For most risk factors, their dose-response relationships with LE were non-linear and depended on the presence of other factors. In individuals with high levels of risk, eliminating or reducing exposure to multiple factors could improve LE by several years, even at a relatively advanced age.

Smoking history: relationships with inflammatory markers, metabolic markers, body composition, muscle strength, and cardiopulmonary capacity in current smokers

OBJECTIVE

To determine the relationships that smoking history has with inflammatory markers, metabolic markers, body composition, muscle strength, and cardiopulmonary capacity in current smokers.

METHODS

This was a cross-sectional study involving 65 smokers (age range: 18-60 years). On three non-consecutive days, each participant was evaluated in terms of smoking history, pre-existing comorbidities, lung function (by spirometry), peripheral muscle strength (by dynamometry), body composition (by bioelectrical impedance analysis), levels of metabolic/inflammatory markers, and maximum cardiopulmonary capacity (by treadmill exercise test). We evaluated the relationships that smoking history has with inflammatory markers, metabolic markers, body composition, muscle strength, and cardiopulmonary capacity, using logarithmic transformation of the data and calculating Pearson's correlation coefficient and for partial correlations adjusted for age, gender, body mass index (BMI), and comorbidities. To identify the influence of smoking history on pre-existing comorbidities, we used a logistic regression model adjusted for age, BMI, and duration of smoking.

RESULTS

Smoking history correlated significantly, albeit weakly, with triglyceride level (r = 0.317; p = 0.005), monocyte count (r = 0.308; p = 0.013), and waist circumference (r = 0.299; p = 0.017). However, those correlations did not retain their significance in the adjusted analysis. In the logistic regression model, smoking more than 20 cigarettes/day correlated significantly with the presence of metabolic diseases (OR = 0.31; 95% CI: 1.009-1.701; p = 0.043).

CONCLUSIONS

In this sample of smokers, smoking history correlated positively with the triglyceride level, the monocyte count, and waist circumference. The prevalence of metabolic disease was highest in those who smoked more than 20 cigarettes/day.

Incidence of cardiovascular disease and its associated risk factors in at-risk men and women in the United Arab Emirates: a 9-year retrospective cohort study

Background

Cardiovascular disease (CVD) is the leading cause of mortality worldwide; however, the epidemiology of CVD among nationals from the United Arab Emirates (UAE) remains unknown. This study aimed to estimate the 9-year incidence rate of CVD and determine the risk factors associated with CVD among UAE nationals at high cardiovascular risk. In addition, we investigated whether sex was an important modifier of the risk factors associated with incident CVD in this population.

Methods

A retrospective cohort study was conducted on 977 subjects, including 492 women, aged ≥18 years, who did not have histories of CVD, and who had ≥1 CVD risk factors. Multivariable Cox proportional hazards regression analyses stratified by sex were used to examine the predictors of major CVD events, namely, myocardial infarction (MI), stroke, and acute peripheral arterial occlusion.

Results

During a median follow-up period of 8.9 years, the incidence rate of major CVD was 12.7 per 1000 person-years (95% confidence interval [CI] 10.4–15.4), and among men and women were 16.8 (95% CI 12.9–21.4) and 9.0 (95% CI 6.4–12.4) per 1000 person-years, respectively. Major CVD and MI were significantly more frequent among men than women, and the stroke and acute peripheral arterial occlusion rates were similar for both sexes. Multivariable Cox analyses showed that the systolic blood pressure, estimated glomerular filtration rate, and serum glycosylated hemoglobin A1c level were strong predictors of major CVD in both sexes. Among women, the total cholesterol (TC)-to-high-density lipoprotein-cholesterol (HDL-C) ratio (hazard ratio [HR] 1.44, 95% CI 1.02–2.04) was an additional independent predictor of major CVD. Age (HR 1.50, 95% CI 1.19–1.89) and a history of smoking (HR 1.80, 95% CI 1.07–3.02) were significant risk factors associated with major CVD in men.

Conclusions

Among high-risk UAE nationals who did not have histories of CVD, the risk of major CVD was associated with high systolic blood pressure, a low estimated glomerular filtration rate, and poorly controlled diabetes. The high TC-to-HDL-C ratios, especially among women, and smoking among men, are modifiable risk factors that should be managed aggressively.

Electronic supplementary material

The online version of this article (10.1186/s12872-019-1131-2) contains supplementary material, which is available to authorized users.

Low serum folic acid can be a potential independent risk factor for erectile dysfunction: a prospective case-control study

PURPOSE

The purpose of the study was to compare serum level of folic acid (FA) in patients with erectile dysfunction (ED) versus healthy controls and to assess its correlation with other well-known confounders for ED.

METHODS

Our prospective study compared FA in 60 patients with ED versus 30 healthy controls. Patients were excluded if they had any hormonal disorders, Peyronie's disease, or decompensated systemic illnesses. ED was evaluated by the validated Arabic version of the abbreviated five-item form of the International Index Of Erectile Function and confirmed by penile duplex. Serum FA level was assayed using ELIZA. Mann-Whitney, Kruskal-Wallis, and Chi-square tests and Spearman correlation were used as appropriate and confirmed by logistic regression model.

RESULTS

Our study revealed that the median FA of the cases and the controls were 7.1 ng/mL and 13.4 ng/mL, respectively, and this difference was of high statistical significance (p < 0.001). Moreover, our study demonstrated significant relations between serum FA with DM, HTN, smoking, age, and cholesterol (p 0.01, 0.03, 0.014, 0.001, and 0.015, respectively). Our study showed that the best cut-off point of serum FA to detect patients with ED was found to be ≤ 9.42 with sensitivity of 80.00%, specificity of 93.33% and area under curve (AUC) of 91.3%.

CONCLUSION

Serum FA level decreased as the severity of ED increased even after adjustment of age, serum testosterone, DM, HTN, and smoking. FA deficiency might be an independent risk factor of ED.

The Mutual Impact of Smoking and Low Cholesterol on All-Cause, Non-Cardiovascular, and Cardiovascular Mortalities in Males

The aim of the current study was to examine the possible relationship between the mutual effects of smoking and low cholesterol on all-cause, non-cardiovascular, and cardiovascular mortalities in males. This is a prospective cohort study of 30,179 males sampled from the Risk Factors and Life Expectancy (RIFLE) studies in the Italian population. The RIFLE data are from 19 different large-scale studies over a 9.5-year follow-up period. The Cox Proportional Hazard model was applied to analyze the data. The associations are presented as hazard ratios (HRs) with 95% confidence interval (CI). Cholesterol data were reported in categories. There were significant mortality risk mutual associations for never-smokers and those in the low cholesterol category (<160 mg/dl) for all-cause (HR = 3.13, 95% CI [1.69, 5.80]), and non-cardiovascular disease (CVD) (HR = 6.51, 95% CI [2.19, 19.33]) mortality in men with an insignificant risk for CVD mortality (HR = 1.90, 95% CI [0.85, 4.22]).

There were significant mortality risk associations of the mutual effects of ex-smokers and low cholesterol for non-CVD in the first to third cholesterol categories (HR = 2.50, 95% CI [1.40, 4.46]; HR = 2.65, 95% CI [1.50, 4.71]; HR = 2.12, 95% CI [1.17, 3.82], respectively), but no significant findings for all-cause and CVD deaths.

Furthermore, there were significant mortality risk association of mutual effects of current-smokers and low cholesterol for non-CVD (HR = 1.56, 95% CI [1.11, 2.28]) in the first category of cholesterol level, but insignificant risk associations for all-cause deaths (HR = 1.21, 95% CI [0.89, 1.66]). Interestingly, findings indicate a mutual protective association for current-smokers and low cholesterol (<160 mg/dl) for CVD risk in males (HR = 0.42, 95% CI [0.19, 0.91]).

Findings of this study identified significant mortality risk association for mutual effects of never-smokers, ex-smokers, and low cholesterol for non-CVD. However, there is significant protective association for current-smokers and low cholesterol for CVD.

Serum Homocysteine Levels in Men with and without Erectile Dysfunction: A Systematic Review and Meta-Analysis

OBJECTIVES

Elevated levels of serum homocysteine (Hcy) have been associated with cardiovascular diseases and endothelial dysfunction, conditions closely associated with erectile dysfunction (ED). This meta-analysis was aimed to assess serum Hcy levels in subjects with ED compared to controls in order to clarify the role of Hcy in the pathogenesis of ED.

METHODS

Medline, Embase, and the Cochrane Library were searched for publications investigating the possible association between ED and Hcy. Results were restricted by language, but no time restriction was applied. Standardized mean difference (SMD) was obtained by random effect models.

RESULTS

A total of 9 studies were included in the analysis with a total of 1320 subjects (489 subjects with ED; 831 subjects without ED). Pooled estimate was in favor of increased Hcy in subjects with ED with a SMD of 1.00, 95% CI 0.65-1.35, p < 0.0001. Subgroup analysis based on prevalence of diabetes showed significantly higher SMD in subjects without diabetes (1.34 (95% CI 1.08-1.60)) compared to subjects with diabetes (0.68 (95% CI 0.39-0.97), p < 0.0025 versus subgroup w/o diabetes).

CONCLUSIONS

Results from our meta-analysis suggest that increased levels of serum Hcy are more often observed in subjects with ED; however, increase in Hcy is less evident in diabetic compared to nondiabetic subjects. This study is registered with Prospero registration number CRD42018087558.

Impact of smoking on the observed levels of apolipoprotein B: Data from NHANES 2007-2012

Impact of smoking on the levels of apolipoprotein B (APOB) was evaluated by analyzing data from National Health and Nutrition Examination Survey for the years 2007-2012 for US adolescents aged 12-19 years and adults aged >=20 years. When adjustments were made for the effects of age, gender, race/ethnicity, body mass index, and poverty income ratio, smoking did not influence the observed levels of APOB for either adolescents or adults. Moreover, even the variables that represented intensity of smoking indicated, for example, by the number of days participants smoked during the last five days and/or the number of cigarettes smoked on the days they were smoked did not affect the levels of APOB. Also, type of smoking, cigarettes only, cigars only, or smokeless products only did not affect the levels of APOB. Every two years, adjusted levels of APOB decreased by 2.5% for adolescents and by 1.8% for adults.