{
  "abstract": "Background While smoking is inversely associated with Parkinson’s disease (PD) risk, its relationship with amyotrophic lateral sclerosis (ALS) and multiple system atrophy (MSA) remains unclear, particularly in Asian populations. We investigated these associations in a Chinese case–control study.Methods We recruited newly diagnosed ALS (n=430), MSA (n=271), PD (n=523) cases and hospital-based controls (n=1033) in Sichuan, China. Logistic regression models were used to evaluate associations between smoking and disease risks, adjusting for demographic, lifestyle and occupational factors.Results Compared with never-smokers, the adjusted ORs and 95% CIs of ALS for current and former smokers were 1.00 (0.61 to 1.65) and 1.79 (1.01 to 3.17), respectively. For MSA, ORs were 1.27 (0.73 to 2.23) for current smokers and 2.54 (1.41 to 4.60) for former smokers. Individuals who quit within 4 years before diagnosis showed the highest risk of ALS (OR=1.93, 95% CI 0.96 to 3.88) and MSA (OR=2.09, 95% CI 1.11 to 3.93). For both ALS and MSA, no consistent trend was found with increasing smoking duration or pack-years. In contrast, ever-smokers had a significantly lower PD risk (OR=0.49, 95% CI 0.33 to 0.71), particularly current smokers (OR=0.30, 95% CI 0.19 to 0.48). Longer smoking duration and higher cumulative smoking were also linked to PD risk with clear negative exposure-response patterns (P trend=0.039 and 0.029, respectively).Conclusions Consistent with findings in non-Asian populations, smoking was inversely associated with PD risks in the Chinese population. For ALS and MSA, we found evidence suggestive of positive relationships with cigarette smoking, but no clear exposure-response relationships were observed.",
  "authors": [
    {
      "affiliations": [
        "Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands"
      ],
      "name": "Jia Nie"
    },
    {
      "affiliations": [
        "Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands"
      ],
      "name": "Susan Peters"
    },
    {
      "affiliations": [
        "Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands"
      ],
      "name": "Calvin B Ge"
    },
    {
      "affiliations": [
        "Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands"
      ],
      "name": "Lützen Portengen"
    },
    {
      "affiliations": [
        "Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland, USA"
      ],
      "name": "Nathaniel Rothman"
    },
    {
      "affiliations": [
        "Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland, USA"
      ],
      "name": "Wei Hu"
    },
    {
      "affiliations": [
        "Department of Neurology, Laboratory of Neurodegenerative Disorders, Rare Disease Center, West China Hospital of Sichuan University, Chengdu, Sichuan, China"
      ],
      "name": "Ruwei Ou"
    },
    {
      "affiliations": [
        "Department of Neurology, Laboratory of Neurodegenerative Disorders, Rare Disease Center, West China Hospital of Sichuan University, Chengdu, Sichuan, China"
      ],
      "name": "QianQian Wei"
    },
    {
      "affiliations": [
        "Department of Neurology, Laboratory of Neurodegenerative Disorders, Rare Disease Center, West China Hospital of Sichuan University, Chengdu, Sichuan, China"
      ],
      "name": "Lingyu Zhang"
    },
    {
      "affiliations": [
        "Center of Gerontology and Geriatrics, National Clinical Research Center for Geriatrics, West China Hospital of Sichuan University, Chengdu, Sichuan, China"
      ],
      "name": "Yanbing Hou"
    },
    {
      "affiliations": [
        "Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland, USA"
      ],
      "name": "Qing Lan"
    },
    {
      "affiliations": [
        "Department of Neurology, Laboratory of Neurodegenerative Disorders, Rare Disease Center, West China Hospital of Sichuan University, Chengdu, Sichuan, China"
      ],
      "name": "Hui-Fang Shang"
    },
    {
      "affiliations": [
        "Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands",
        "Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands"
      ],
      "name": "Roel Vermeulen"
    }
  ],
  "title": "Smoking and the risk of neurodegenerative diseases in a Chinese case–control study",
  "uid": "02593c6c-1a4c-5c19-8ded-fa7f3346e294"
}