Body mass index and stroke incidence in Japanese community residents: The Jichi Medical School (JMS) Cohort Study

Abstract

BackgroundHigh body mass index (BMI) has been reported as a risk factor for cardiovascular events in Western countries, while low BMI has been reported as a risk factor for cardiovascular death in Asian countries, including Japan. Although stroke is a major cause of death and disability in Japan, few cohort studies have examined the association between BMI and stroke incidence in Japan. This study aimed to examine the association between BMI and stroke incidence using prospective data from Japanese community residents.MethodsData were analyzed from 12,490 participants in the Jichi Medical School Cohort Study. Participants were categorized into five BMI groups: ≤18.5, 18.6–21.9, 22.0–24.9, 25.0–29.9, and ≥30.0 kg/m2. Multivariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using the Cox proportional hazard model. The group with a BMI of 22.0–24.9 kg/m2 was used as the reference category.ResultsDuring mean follow-up of 10.8 years, 395 participants (207 men and 188 women) experienced stroke, including 249 cerebral infarctions and 92 cerebral hemorrhages. Men with a BMI ≤18.5 kg/m2 (HR 2.11; 95% CI, 1.17–3.82) and women with a BMI ≥30.0 kg/m2 (HR 2.25; 95% CI, 1.28–5.08) were at significantly higher risk for all-stroke. Men with a BMI ≤18.5 kg/m2 were at significantly higher risk for cerebral infarction (HR 2.15; 95% CI, 1.07–4.33).ConclusionsThe association between BMI and stroke incidence observed in this population was different than those previously reported: low BMI was a risk factor for all-stroke and cerebral infarction in men, while high BMI was a risk factor for all-stroke in women.

Association between Stroke and Cognitive Decline in Community Dwelling Older and Oldest People: The SONIC Study

“…In general, the incidence of stroke increases with age, occurring in up to 69% of individuals older than 65 years and 34.4% in those older than 75 years [2]. Nevertheless, survival after stroke is a major cause of lifelong disability and places a heavy cost of care on Japan's LTC insurance system [3].…”

“…Therefore, understanding the risk factors of cognitive decline in stroke patients is necessary so that preventive strategies against cognitive impairment and dementia, especially in older and oldest people, can be identified. The risk factors of cognitive decline after stroke are numerous, as reported in previous studies, including: age [7][8][9][10][11][12][13][14][15], sex [7,9,10],vascular risk factors such as hypertension [7,9,13,16],diabetes mellitus [10, 12-14, 17, 18], dyslipidemia [15,19], atrial fibrillation [20][21][22],and current smoking [9,16],and social factors including educational level [7, 9-11, 14, 15],frequency of going outside [23],and LTC service used [3].The relationship between risk factors and post-stroke cognitive decline reported in previous studies may differ due to cognitive function assessment methods, but the MoCA-J is considered a useful cognitive assessment for detecting mild cognitive impairment (MCI), and its results are used to offer recommendations in a primary clinical setting and for geriatric health screening in the community. Moreover, the MoCA-J has been shown to detect cognitive decline over a 2-year period in older people with MCI and early-stage Alzheimer's disease [24].…”

Factors related to 6-month mortality after the first-ever stroke

“…More mortality of low BMI results from pneumonia, nutritional deficiency, and less resistance to infections. [ 34 35 ] Overweight and obese patients had 2.23 (95% CI: 1.53–4.81) times more HR 6-month mortality than patient with normal BMI. In a study done in Japan, the Jichi Medical School cohort study, it was found that underweight (BMI below 18.5) men with an HR of 2.11; 95% CI: 1.17–3.82 were significantly at a greater risk of mortality.…”

“…However, women with BMI of 30 and beyond (HR 2.25, 95% CI: 1.28–5.08) were significantly at a greater risk of mortality. [ 34 ]…”

The Importance of Stroke as a Risk Factor of Cognitive Decline in Community Dwelling Older and Oldest peoples : The SONIC Study

“…Therefore, understanding stroke as a risk factor of cognitive decline is necessary so that preventive strategies against cognitive impairment and dementia, especially in older and oldest people, can be identified. The risk factors of cognitive decline related to stroke are numerous, as reported in previous studies, including: age [9][10][11][12][13][14][15][16][17], sex [9,11,12], vascular risk factors such as hypertension [9,11,15,18], diabetes mellitus [12, 14-16, 19, 20], dyslipidemia [17,21], atrial fibrillation [22][23][24], and current smoking [11,18], and social factors including educational level [9, 11-13, 16, 17], frequency of going outside [25], and LTC service used [26]. The relationship between stroke as a risk factor with cognitive decline reported in previous studies may differ due to cognitive function assessment methods, but the MoCA-J is considered a useful cognitive assessment for detecting mild cognitive impairment (MCI), and its results are used to offer recommendations in a primary clinical setting and for geriatric health screening in the community.…”