Relationships among smoking habits, airflow limitations, and metabolic abnormalities in school workers

Much lower prevalence and mortality of chronic obstructive pulmonary disease in Japan than in the US despite higher smoking rates: A meta analysis/systematic review

BACKGROUND

A recent systematic review showed Japan's mortality from chronic obstructive pulmonary disease (COPD) is the lowest among 204 countries, despite notably higher smoking rates in men in Japan than in the US. This study aims to compare (1) trends in smoking rates, (2) trends in COPD mortality, and (3) the spirometry-based COPD prevalence in the general adult population between Japan and the US.

METHODS

Age- and sex-specific smoking rates from the 1980s through 2010s and COPD mortality from 1999 through 2019 were obtained from national surveys and official statistics (International Classification of Diseases-10th codes J40-44), respectively. A systematic review and meta-analysis was performed to estimate COPD prevalence in Japan, while the National Health and Nutrition Examination Survey 2007-2012 was used for the US. A fixed ratio of 0.7 of forced expiratory volume in the first second of forced vital capacity was used to define COPD.

RESULTS

Over the past four decades, men in Japan consistently had 20-30% higher smoking rates than their US counterparts. From 1999-2019, age-adjusted COPD mortality in men in Japan was only a third of the US, whereas that in women was less than a tenth in 2019. Synthesizing data from 11 studies, involving 89,955 participants, Japan's COPD prevalence was more than 10% lower than in the US in almost all age groups for both sexes.

CONCLUSIONS

This study showed markedly lower rates of COPD in Japan than in the US. Investigating factors contributing to the paradoxical observations could lead to advancing COPD risk reduction strategies.

The Effects of Smoking on Metabolic Syndrome and Its Components Using Causal Methods in the Iranian Population

Background

The aim of this study was to estimate the effect of smoking on metabolic syndrome (MS) and its components applying inverse probability-of-treatment weighting (IPTW) and propensity score (PS) matching.

Methods

Using data from Tehran Lipid and Glucose Study, 4857 participants aged over 20 years with information on smoking and confounders in the third phase (2005-2008) were included, and the MS was assessed in the fifth phase (2011-2014). IPTW and PS matching were used to adjust for confounders.

Results

Based on average treatment effect (ATE) estimates, smoking decreased the risk of hypertension (RR: 0.62; 95% CI: 0.43, 0.88), but increased the risk of low HDL cholesterol (1.20; 0.98, 1.48). Similarly, the average treatment effect in the treated (ATT) estimates using IPTW and PS matching suggested that smoking decreased the risk of hypertension (0.63; 0.52, 0.76, and 0.68; 0.54, 0.85), and increased the risk of low HDL cholesterol (1.24; 1.07, 1.43, and 1.28; 1.06, 1.54), respectively.

Conclusions

Smoking seems to increase the risk of low HDL cholesterol but decreases the risk of hypertension.

The relationship of cigarette smoking in Japan to lung cancer, COPD, ischemic heart disease and stroke: A systematic review

Background:  To present up-to-date meta-analyses of evidence from Japan relating smoking to major smoking-related diseases.  Methods:  We restricted attention to lung cancer, chronic obstructive pulmonary disease (COPD), ischemic heart disease (IHD) and stroke, considering relative risks (RRs) for current and ex-smokers relative to never smokers.  Evidence by amount smoked and time quit was also considered.  For IHD and stroke only, studies had to provide age-adjusted RRs, with age-specific results considered.  For each disease we extended earlier published databases to include more recent studies.  Meta-analyses were conducted, with random-effects RRs and tests of heterogeneity presented.  Results:  Of 40 studies, 26 reported results for lung cancer and 7 to 9 for each other disease.  For current smoking, RRs (95%CIs) were lung cancer 3.59 (3.25-3.96), COPD 3.57 (2.72-4.70), IHD 2.21 (1.96-2.50) and stroke 1.40 (1.25-1.57).  Ex-smoking RRs were lower.  Data for lung cancer and IHD showed a clear tendency for RRs to rise with increasing amount smoked and decrease with increasing time quit.  Dose-response data were unavailable for COPD and unclear for stroke, where the association was weaker.  Conclusions:  Compared to studies in other Asian and Western countries, current smoking RRs were quite similar for IHD and stroke.  The comparison is not clear for COPD, where the Japanese data, mainly from cross-sectional studies, is limited.  For lung cancer, the RRs are similar to those in other Asian countries, but substantially lower than in Western countries.  Explanations for this are unclear, but less accurate reporting of smoking by Japanese may contribute to the difference.

Impact of treatment with TNF antagonists on total cholesterol in patients with ankylosing spondylitis and psoriatic arthritis

The objective of the study was to analyze the impact of TNF antagonists (TNFa) on the total cholesterol and triglycerides on ankylosing spondylitis (AS) and psoriatic arthritis (PsA). In this single-centre observational study of AS and PsA patients, differences in triglyceride and total cholesterol levels and frequency of hypertriglyceridemia and hypercholesterolemia at 3 and 6 months were analysed in patients treated and not treated with TNFa. General estimation equations and linear regression analysis were used to investigate associations between disease activity and lipid levels and to identify predictors of change. One hundred fifty-seven patients treated, and 157 not treated with TNFa, were included in the study. A transient increase in cholesterol level from baseline to 3 months in TNFa-treated patients was the only statistically significant effect (P < 0.001). Persistent percentages of hypertriglyceridemia and hypercholesterolemia from baseline were significantly higher in not treated than in TNFa-treated patients (P = 0.009 and P = 0.001, respectively). Inverse associations between changes in cholesterol level and Bath Ankylosing Spondylitis Disease Activity Index (P = 0.011) and CRP (P < 0.001), but not Disease Activity Score in 28 Joints (P = 0.095) were found in the whole group. In AS and PsA patients treated with TNFa, mild and transient changes in cholesterol but not in triglyceride levels were associated with changes in disease activity.

Prevalence, awareness, characteristics, and health outcomes associated with COPD at-risk status among adults in Japan

OBJECTIVES

We examined the prevalence of chronic obstructive pulmonary disease (COPD) diagnosed and at-risk status, and public awareness of COPD among adults in Japan, as well as respondent characteristics and health outcomes compared with controls.

METHODS

Regression models used 2012 National Health and Wellness Survey in Japan data to compare COPD-diagnosed, at-risk, and healthy adults (aged ≥18) on demographics, health behaviors, health-related quality of life (HRQoL), productivity and healthcare resource use.

RESULTS

Among n = 29,978 respondents, diagnosed COPD prevalence was 0.9%; 26.9% were at-risk. Relative to controls, those at-risk and diagnosed with COPD had significantly greater healthcare resource use, with lower productivity and HRQoL. Fewer than 20% of respondents were aware of COPD.

CONCLUSIONS

Over 25% of adult Japanese respondents were at-risk for COPD and had health outcomes impairments relative to controls. Efforts to increase awareness among the general public are needed.