Time to First Cigarette and the Risk of Hypertension: A Nationwide Representative Study in Korea

Smoking timing, genetic susceptibility, and the risk of incident atrial fibrillation: a large prospective cohort study

AIMS

Although smoking is a well-known risk factor for atrial fibrillation (AF), the association of smoking timing with AF risk remains unclear. This study aimed to prospectively investigate the association of smoking timing with the risk of incident AF and test the modification effect of genetic susceptibility.

METHODS AND RESULTS

A total of 305 627 participants with detailed information for time from waking to the first cigarette were enrolled from UK Biobank database. The Cox proportional hazard model was employed to assess the relationship between smoking timing and AF risk. The weighted genetic risk score for AF was calculated. Over a median 12.2-year follow-up, 13 410 AF cases were documented. Compared with non-smokers, time from waking to the first cigarette showed gradient inverse associations with the risk of incident AF (P-trend <0.001). The adjusted hazard ratio related to smoking timing was 1.13 [95% confidence interval (CI): 0.96-1.34] for >120 min, 1.20 (95% CI: 1.01-1.42) for 61-120 min, 1.34 (95% CI: 1.19-1.51) for 30-60 min, 1.43 (95% CI: 1.26-1.63) for 5-15 min, and 1.49 (95% CI: 1.24-1.63) for <5 min, respectively. Additionally, we found that the increased risk of AF related to shorter time from waking to the first cigarette was strengthened by the genetic susceptibility to AF.

CONCLUSION

Our findings suggest gradient inverse association between time from waking to the first cigarette and risk of incident AF, and the association is strengthened by the genetic susceptibility to AF.

Smoking Timing, Healthy Diet, and Risk of Incident CKD Among Smokers: Findings From UK Biobank

RATIONALE & OBJECTIVE

Although smoking is a recognized risk factor for chronic kidney disease (CKD), the relationship between the time smoking is initiated after awakening each day and CKD remains largely unstudied. This study examined the association between this timing and the risk of CKD, and the potential interactions of smoking timing with other risk factors for the occurrence of CKD.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

A total of 32,776 participants in the UK Biobank with complete data on the time from waking to the first cigarette and free of prevalent CKD were included.

EXPOSURE

Time from waking to the first cigarette.

OUTCOME

Incident CKD cases.

ANALYTICAL APPROACH

Cox proportional hazards regression was used to investigate the associations between the time smoking is initiated each day and the risk of CKD. The potential interactions of smoking timing with risk factors in relationship to CKD risk were assessed on both multiplicative and additive scales.

RESULTS

During a median follow-up period of 12 years, 940 incident CKD cases occurred. Shorter durations of time from waking to the first cigarette were associated with a higher risk of incident CKD (P trend=0.01). Compared with>120 minutes, the adjusted hazard ratio (HR) associated with smoking timing was 1.28 (95% CI, 0.92-1.80) for 61-120 minutes, 1.48 (95% CI, 1.11-1.96) for 30-60 minutes, 1.36 (95% CI, 1.01-1.88) for 5-15 minutes, and 1.70 (95% CI, 1.22-2.37) for<5 minutes, respectively. Furthermore, there was a significant additive interaction and multiplicative interactions between the timing of smoking and a healthy diet score (P for additive interaction=0.01; P for multiplicative interaction = 0.004).

LIMITATIONS

Generalizability, possible residual confounding, limiting causal inference.

CONCLUSIONS

These findings reveal a significant association between the shorter time from waking to the first cigarette and a higher CKD risk. The magnitude of these associations was greater in the setting of an unhealthy diet.

PLAIN-LANGUAGE SUMMARY

This study explored the association of the daily timing of first cigarette smoking and the occurrence of kidney disease. Further, we addressed whether this association was influenced by the quality of the diet. The study found that smoking very soon after waking, especially when combined with a poorer quality diet, was associated with a significantly increased risk of developing chronic kidney disease. This research emphasizes the value of healthier lifestyle choices for kidney health.

Smoking timing, genetic susceptibility and the risk of incident type 2 diabetes: A cohort study from the UK Biobank

AIM

To prospectively assess the association of smoking timing with the risk of type 2 diabetes (T2D) and examine whether smoking amount or genetic susceptibility might modify the relationship.

MATERIALS AND METHODS

A total of 294 815 participants without diabetes from the UK Biobank, including non-smokers and smokers with data on the time from waking to first cigarette, were included. Cox proportional hazards models were used to evaluate the association between smoking timing and the risk of incident T2D.

RESULTS

During a median follow-up time of 12 years, a total of 9937 incident cases of T2D were documented. Compared with non-smokers, a shorter time from waking to first cigarette was significantly associated with a higher risk of incident T2D (P for trend < .001). In the fully adjusted model, the hazard ratios (HRs) (95% confidence interval) associated with smoking timing were 1.46 (1.17-1.81) for more than 2 hours, 1.51 (1.21-1.87) for 1-2 hours, 1.58 (1.34-1.85) for 30-60 minutes, 1.86 (1.57-2.21) for 5-15 minutes and 2.01 (1.60-2.54) for less than 5 minutes. We found that even among those who reported being light smokers, those with the shortest time from waking to first cigarette had a 105% higher risk of T2D with an HR of 2.05 (1.52-2.76), which was comparable with heavy smokers. The genetic risk score for T2D did not modify this association (P-interaction = .51).

CONCLUSIONS

Our findings indicate that shorter time from waking to first cigarette is significantly associated with a higher risk of incident T2D.

CYP17A1-ATP2B1 SNPs and Gene-Gene and Gene-Environment Interactions on Essential Hypertension

Background: The association between the CYP17A1 and ATP2B1 SNPs and essential hypertension (referred to as hypertension) is far from being consistent. In addition to the heterogeneity of hypertension resulting in inconsistent results, gene–gene and gene–environment interactions may play a major role in the pathogenesis of hypertension rather than a single gene or environmental factor.

Methods: A case–control study consisting of 1,652 individuals (hypertension, 816; control, 836) was conducted in Maonan ethnic minority of China. Genotyping of the four SNPs was performed by the next-generation sequencing technology.

Results: The frequencies of minor alleles and genotypes of four SNPs were different between the two groups (p < 0.001). According to genetic dominance model analysis, three (rs1004467, rs11191548, and rs17249754) SNPs and two haplotypes (CYP17A1 rs1004467G-rs11191548C and ATP2B1 rs1401982G-rs17249754A) were negatively correlated, whereas rs1401982 SNP and the other two haplotypes (CYP17A1 rs1004467A-rs11191548T and ATP2B1 rs1401982A-rs17249754G) were positively associated with hypertension risk (p ≤ 0.002 for all). Two best significant two-locus models were screened out by GMDR software involving SNP–environment (rs11191548 and BMI ≥ 24 kg/m²) and haplotype–environment (CYP17A1 rs1004467G-rs11191548C and BMI ≥ 24 kg/m²) interactions (p ≤ 0.01). The subjects carrying some genotypes increased the hypertension risk.

Conclusions: Our outcomes implied that the rs1004467, rs11191548, and rs17249754 SNPs and CYP17A1 rs1004467G-rs11191548C and ATP2B1 rs1401982G-rs17249754A haplotypes have protective effects, whereas the rs1401982 SNP and CYP17A1 rs1004467A-rs11191548T and ATP2B1 rs1401982A-rs17249754G haplotypes showed adverse effect on the prevalence of hypertension. Several SNP–environment interactions were also detected.

Association between Time to First Cigarette and Health-Related Quality of Life of Middle-Aged Male Current Smokers: A Nationwide Representative Study in Korea

BACKGROUND

Although many studies have demonstrated that the first cigarette in the morning increases the prevalence of smoking-related morbidity, limited studies have examined the impact of time to first cigarette (TTFC) on the health-related quality of life (HRQoL). Thus, we assessed this relationship using nationally-representative data from the Korea National Health and Nutrition Examination Survey VII-1 (2016).

METHODS

We conducted a cross-sectional study using data from 577 current male smokers aged 30-59 years, after excluding those with a certain disease. Participants were divided into four categories according to TTFC (≤5 min, 6-30 min, 31-60 min, >60 min). HRQoL was measured using self-reported EuroQol-5 (EQ-5D). The relationship between TTFC and EQ-5D index was analyzed using a multivariate-adjusted generalized linear model to assess how HRQoL varies according to TTFC. After adjusting for confounders, a multivariate-adjusted logistic regression analysis was performed to identify which of the five dimensions of the EQ-5D affected the HRQoL according to TTFC.

RESULTS

The generalized linear analysis indicated that as TTFC decreased (6-30 min, 31-60 min vs. >60 min), the EQ-5D index score decreased significantly (P=0.037). Shorter TTFC (≤5 min vs. >60 min) was associated with higher pain/discomfort (odds ratio [OR], 3.82; 95% confidence interval [CI], 1.39-10.48) and anxiety/depression (OR, 7.58; 95% CI, 1.75-32.88).

CONCLUSION

Higher nicotine dependence was associated with impaired HRQoL. These results may be used to improve smoking cessation treatment outcomes.

Effect of frequency and pattern of night shift on hypertension risk in female nurses: a cross-sectional study

OBJECTIVES

Understanding the effect of night shift on hypertension risk in nurses is important to improve the health of nurses and ensure patient safety. This study aimed to evaluate the effect of the frequency and pattern of night shift on hypertension risk and the interaction of them in female nurses.

METHODS

This cross-sectional study constituted 84 697 female nurses in 13 cities in China. The main contents of the survey included SBP, DBP, the frequency and pattern of night shift, and some other factors that might be associated with hypertension. Logistic regression analyses were used to calculate ORs and 95% CIs to estimate the effect of the frequency and pattern of night shift on hypertension risk and the interaction of them in relation to hypertension risk.

RESULTS

Having more than 5 to 10 or more than 10 night shifts per month were significantly more likely to be hypertensive (OR 1.19, 95% CI 1.10-1.28; OR 1.32, 95% CI 1.13-1.54), whereas having less than or equal to 5 night shifts per month was not (OR 1.05, 95% CI 0.95-1.16). The patterns of night shift were all associated with a higher probability of hypertension and participants engaging in rapidly rotating night shift had a lower OR (1.14) than those having slowly rotating night shift (1.23) and permanent night shift (1.46). No significant interaction was observed between the frequency and the pattern of night shift (Pinteraction = 0.281).

CONCLUSION

The frequency and pattern of night shift were associated with hypertension risk in female nurses and no significant interaction was observed between them.

'Time to first tobacco cigarette soon after waking' occurs more often among underage newly incident smokers in the United States, 2004-2017

AIMS

Time to first cigarette (TTFC) after waking is a highly regarded and readily measured manifestation of a tobacco dependence process. We aim to estimate short TTFC as it occurs very soon after the onset of cigarette smoking (CS) in a community sample of newly incident smokers, all 12-21 years of age, and to study risk variation with the age of CS onset.

METHODS

United States National Surveys on Drug Use and Health, 2004-2017, drew large nationally representative samples of 12-to-21-year-old community residents, and used computerized self-interviews to measure tobacco cigarette smoking, the Fagerstrom TTFC construct, and related variables. A 'short' TTFC was defined as smoking the first cigarette after waking up within 30 min vs. 'long' TTFC or smoking more than 30 min. We studied 8188 newly incident smokers, all assessed within six months after the first puff. Estimated age-specific cumulative incidence proportions (CIP) and odds ratios (OR) are estimated and compared, with due attention to complex survey design and weights.

RESULTS

Among underage newly incident smokers (12-17 years old), an estimated 5.2% experienced short TTFC within 6 months after CS onset (95% CI = 4.4%, 6.2%), versus 3.7% for older new smokers (18-21 years; 95% CI = 2.8%, 4.6%). Underage smokers are 1.5 times more likely to develop short TTFC compared to older initiates (95% CI = 1.1, 2.1). No male-female variations are seen, but exploratory analysis disclosed findings that involve Census-defined race-ethnicity subgroups. Non-Hispanic African-American initiates are twice as likely to develop short TTFC, and Hispanic initiates are less likely to develop short TTFC, as compared with non-Hispanic White smokers.

CONCLUSIONS

Based on US community samples our study offers new evidence about TTFC formation observed within six months after the first puff when cigarette smoking starts before age 18 years.