Xianjia Ning

Trends of hypertension prevalence, awareness, treatment and control in rural areas of northern China during 1991-2011

This study aims to investigate the trends in prevalence, awareness, treatment and control of hypertension among rural residents aged 35–74 years in northern China during the country’s rapid economic development from 1991 to 2011. Two surveys, conducted in 1991and 2011, included 2196 and 1939 participants aged 35–74 years from same villages in Ji County, Tianjin of China, respectively. The prevalence of hypertension, adjusted by age and gender using the world standard population in 2000, increased 30% (39.9% vs 51.7%) between 1991 and 2011. The increase was greatest (68%) in women aged 35–44 years. Meanwhile, the prevalence of stage II hypertension increased by 75% overall, with a 4-fold increase in men aged 45–54 years. Although the awareness, treatment and control of hypertension increased significantly during the same period, they remained unacceptably poor. In conclusion, the community-based surveys showed that the prevalence of hypertension in rural residents of northern China aged 35–74 years increased rapidly over the past 20 years, and most dramatically in young women. Efforts in the primary prevention of hypertension, particularly for young women, and promoting education for hypertension awareness, treatment and control are of paramount importance in rural China.

Sex Differences in Trends of Incidence and Mortality of First-Ever Stroke in Rural Tianjin, China, From 1992 to 2012

Background and Purpose— Sex differences in secular trends of stroke incidence are rarely reported. We aimed to explore sex differences in incidence and mortality of stroke in rural China from 1992 to 2012. Methods— In 1992, 14 920 residents were recruited to participate in the Tianjin Brain Study, a population-based study on stroke surveillance. Stroke events and all deaths were annually registered. Results— We observed 908 incident strokes (366 in women) from 1992 to 2012. Women were significantly younger than men (64±12 versus 68±11 years) in 1992 to 1998 (P=0.024). The incidence of first-ever stroke per 100 000 person-years for men was 166 in 1992 to 1998, 227 in 1999 to 2005, and 376 in 2006 to 2012; for women, the rates were 86 (1992–1998), 148 (1999–2005), and 264 (2006–2012). From 1992 to 2012, the incidence grew annually by 5.8% in men and 8.0% in women. The male/female incidence ratio declined significantly: 1.9 in 1992 to 1998, 1.5 in 1999 to 2005, and 1.4 in 2006 to 2012. There were no significant sex differences in mortality. The prevalence of obesity and diabetes mellitus, the levels of total cholesterol and triglycerides, and the age of menopause and reproductive years in women concurrently increased in 2011. Conclusions— There was a significant increase in the incidence of first-ever stroke in women annually and a declining trend in the male/female rate ratio in rural China during the past 21 years. These results suggest that stroke will become one of the major diseases affecting women in future decades in China.

Increasing stroke incidence and prevalence of risk factors in a low-income Chinese population

Objective: We investigated secular trends in incidence of first-ever stroke and the prevalence of stroke risk factors within the same population in rural China. Methods: In 1985, 15,438 residents from a township of Tianjin, China, were recruited to the Tianjin Brain Study, a population-based stroke surveillance study. Stroke events and all deaths were registered annually. Because imaging technology was first available in 1992, we analyzed the incidence of first-ever stroke over 3 study periods—1992–1998, 1999–2005, and 2006–2012—from 1992 to 2012. Risk factor surveys were conducted in 1991 and 2011. Results: The age-standardized incidence of first-ever stroke per 100,000 person-years increased rapidly from 124.5 in 1992–1998 to 190.0 in 1999–2005 and to 318.2 in 2006–2012; incidence increased annually by 6.5% overall and by 12% among men aged 45–64 years (p < 0.05). From 1992 to 2012, the age at first-ever stroke in men was earlier by 3.3 years overall, but a similar trend was not observed in women. Concurrently, the prevalence of high fasting glucose and alcohol consumption increased significantly in both men and women, especially in men aged <45 years; the prevalence of obesity and high fasting glucose increased by 8.8-fold and 11-fold, respectively, from 1992 to 2012. Conclusions: The incidence of stroke in rural China increased rapidly, particularly among middle-aged adults, along with a concurrent increase in risk factor prevalence. These findings suggest that without controlling these risk factors, stroke incidence will continue to increase over future decades in China.

Prevalence and Clustering of Cardiovascular Disease Risk Factors among Tibetan Adults in China: A Population-Based Study.

Objectives The prevalence of cardiovascular disease risk factors has increased worldwide. However, the prevalence and clustering of cardiovascular disease risk factors among Tibetans is currently unknown. We aimed to explore the prevalence and clustering of cardiovascular disease risk factors among Tibetan adults in China. Methods In 2011, 1659 Tibetan adults (aged ≥18 years) from Changdu, China were recruited to this cross-section study. The questionnaire, physical examinations and laboratory testing were completed and the prevalence of cardiovascular disease risk factors, including hypertension, diabetes, overweight/obesity, dyslipidemia, and current smoking, were counted. The association between the clustering of cardiovascular disease risk factors and demographic characteristics, and geographic altitude were assessed. Results The age-standardized prevalence of hypertension, diabetes, overweight or obesity, dyslipidemia, and current smoking were 62.4%, 6.4%, 34.3%, 42.7%, and 6.1%, respectively, and these risk factors were associated with age, gender, education level, yearly family income, altitude, occupation, and butter tea consumption (P < 0.05). Overall, the age-adjusted prevalence of clustering of ≥1, ≥2, and ≥3 cardiovascular disease risk factors were 79.4%, 47.1%, and 20.9%, respectively. There appeared higher clustering of ≥2 and ≥3 cardiovascular disease risk factors among Tibetans with higher education level and family income yearly, and those living at an altitude < 3500 m and in a township. Conclusions The prevalence of cardiovascular disease risk factors, especially hypertension, was high in Tibetans. Moreover, there was an increased clustering of cardiovascular disease risk factors among those with higher socioeconomic status, lamas and those living at an altitude < 3500 m. These findings suggest that without the immediate implementation of an efficient policy to control these risk factors, cardiovascular disease will eventually become a major disease burden among Tibetans.

Secular Trends in Prevalence of Overweight and Obesity among Adults in Rural Tianjin, China from 1991 to 2011: A Population-Based Study

Objectives Obesity is associated with cardiovascular diseases and has become the main public health issue in western countries and urban China. However, the prevalence and secular trends of obesity in rural China are currently unknown. The aim of this study was to investigate secular trends in the prevalence of overweight and obesity among rural adults in northern China between 1991 and 2011. Method The prevalence of overweight and obesity was assessed in adults aged 35–74 years living in a rural area in northern China by comparing two surveys that were conducted in 1991 and 2011, respectively. Result The age-adjusted prevalence of overweight increased from 24.5% in 1991 to 42.0% in 2011, and the prevalence of obesity increased from 5.7% in 1991 to 19.6% in 2011. Over the 21-year period, there were significant increases in the prevalence of overweight and obesity for both men and women in all age groups; however, the greatest increase was observed in men aged 35–44 years, with an 10.3-fold increase in obesity prevalence. The prevalence of obesity increased significantly in all risk factors categories, including education levels, blood pressure categories, diabetes previous history, current smoking situation and alcohol drinking situation over the past 21 years overall (p<0.05). The greatest increase in obesity prevalence appeared among those who consumed alcohol (increased by 8.0-fold). Next, there was a 5.3-fold increase in the prevalence of obesity in illiterate residents. Conclusion The prevalence of overweight and obesity has increased rapidly among rural adults in Tianjin over the past 21 years, with the most dramatic increase observed in young men. Therefore, the burden of obesity should serve as a call for action.

Prevalence and Risk Factors of Carotid Plaque Among Middle-aged and Elderly Adults in Rural Tianjin, China.

Carotid plaque (CP) is associated with cardiovascular and cerebrovascular events. However, population-based studies with a large sample are rare in China, particularly those in the low-income population. We aimed to determine the prevalence of CP and the associated risk factors in the rural areas of northern China. Between April 2014 and June 2014, we recruited 3789 residents aged ≥45 years. B-mode ultrasonography was performed to measure the extent of CP. The prevalence of CP was 40.3% overall, 47.1% in men, and 35.4% in women (P < 0.001). The prevalence of CP increased with increasing age (P < 0.001). The participants with CP were more likely to have hypertension, diabetes, high total cholesterol (TC) levels, and high low-density lipoprotein-cholesterol levels and be a current smoker; however, they were less likely to be obese. Multiple logistic regression analysis, adjusted for confounders, indicated that age, male sex, hypertension, diabetes, current smoking, and high LDL-C levels were the independent risk factors for CP. There was a lower risk of CP with alcohol consumption. The findings suggest that managing the conventional risk factors is crucial to reduce the burden of cardiovascular and cerebrovascular diseases in the low-income population in China.

Trends in Age of First-Ever Stroke Following Increased Incidence and Life Expectancy in a Low-Income Chinese Population

Background and Purpose— We investigated secular trends in the age of stroke onset and stroke incidence in a low-income population in rural China. Methods— The study population was recruited from a population-based stroke surveillance study conducted in a township in Tianjin, China, from 1992 to 2014. The trends in mean age and incidence of first-ever stroke were assessed by sex and stroke subtype. Risk factor surveys were conducted in the same population in both 1991 and 2011. Results— A total of 1053 patients experienced first-ever stroke from 1992 to 2014. The mean age of stroke onset in men significantly decreased by 0.28 years annually overall, by 0.56 years for intracerebral hemorrhage, and by 0.22 years for ischemic stroke (P<0.05). However, a similar trend was not observed in women. The age-standardized first-ever stroke incidence in the same population significantly increased across sex and stroke subtypes, increased by 6.3% overall, 5.5% for men, 7.9% for women, 4.6% for intracerebral hemorrhage, and 7.3% for ischemic stroke (P<0.05) during 1992 to 2014. Concurrently, the prevalence of hypertension, diabetes mellitus, obesity, current smoking, and alcohol consumption increased significantly in young and middle-aged adults from 1991 to 2011. Conclusions— The age of stroke onset tends to be younger among low-income population in China after the dramatic increased incidence of stroke during the gradual extension of life expectancy of population in China. These findings suggested that stroke burden will continue to increase in the long time, unless the risk factors in low-income populations are effectively controlled.

Sex Differences in Outcomes and Associated Risk Factors After Acute Ischemic Stroke in Elderly Patients: A Prospective Follow-up Study.

Stroke has a greater effect on women. However, sex differences in outcome and factors associated with outcome among elderly patients are unknown. From January 2009 to December 2011, 810 patients with acute ischemic stroke aged 75 years or older were recruited in China. Clinical profile and risk factors were recorded. Outcomes and associated risk factors at 12 and 36 months after stroke were assessed by sex. Hypertension, diabetes mellitus, dyslipidemias, and obesity prevalence rates were higher in women than in men; opposite trends were found for smoking and alcohol consumption. The mortality rate at 12 months after stroke was significantly greater in men than in women (23.3% versus 16.6%, P = .015). Large-artery atherothrombotic and cardioembolic stroke subtypes were risk factors for mortality, recurrence, and dependency in both sexes. In men, atrial fibrillation was a risk factor of mortality at 12 months after stroke (relative ratio [RR], 2.12; 95% confidence interval [CI], 1.38-3.27), but obesity was a protective factor of mortality at 36 months after stroke (RR, .30; 95% CI, .10-.94). However, in women, atrial fibrillation was a risk factor of recurrence at 12 months (RR, 2.32; 95% CI, 1.31-4.12) and dependency at 36 months after stroke (RR, 7.68; 95% CI, 1.60-36.82). We assessed sex differences in stroke outcomes and associated risk factors at 12 and 36 months after stroke in a large hospital-based stroke registry of elderly patients from Northern China. Thus, it is crucial to emphasize risk management to elderly patients to reduce mortality, recurrence, and dependency after stroke.

Trends in Incidence of Stroke and Transition of Stroke Subtypes in Rural Tianjin China: A Population-Based Study from 1992 to 2012

Objectives The incidence of ischemic stroke has increased and that of hemorrhagic stroke has decreased in urban China; however, the trends in rural areas are unknown. We aimed to explore the secular trends in incidence and transition of stroke subtypes among rural Chinese. Methods This was a population-based stroke surveillance through the Tianjin Brain Study. A total of 14,538 residents in a township of Ji County in Tianjin, China participated in the study since 1985. We investigated the age-standardized stroke incidence (sex-specific, type-specific, and age-specific), the annual proportion of change in the incidence of stroke, and the proportion of intracerebral hemorrhage in the periods 1992–1998, 1999–2005, and 2006–2012, because the neuroimaging technique was available since 1992 in this area. Results The age-standardized incidence per 100,000 person-years increased significantly for both intracerebral hemorrhage (37.8 in 1992–1998, 46.5 in 1999–2005, and 76.5 in 2006–2012) and ischemic stroke (83.9 in 1992–1998, 135.3 in 1999–2005, and 238.0 in 2006–2012). The age-standardized incidence of first-ever stroke increased annually by 4.9% for intracerebral hemorrhage and by 7.3% for ischemic stroke. The greatest increase was observed in men aged 45–64 years for both stroke types (P < 0.001). The proportion of intracerebral hemorrhage was stable overall, increased among men aged 45–64 years, and decreased among men aged ≥65 years. The average age of intracerebral hemorrhage in men reduced by 7.5 years from 1992 to 2012. Conclusion The age-standardized incidence of main stroke subtypes increased significantly in rural China over the past 21 years; the overall proportion of intracerebral hemorrhage was stable, but the incidence increased significantly among middle-aged men. These findings imply that it is crucial to control stroke risk factors in middle-aged men for stroke prevention in future decades.

Increased Stroke Burdens Among the Low-Income Young and Middle Aged in Rural China

Background and Purpose— Although stroke in the young and middle aged accounts for 31% of all strokes in China, the disease burden is unknown. We aimed to determine the secular trends in stroke incidence and the transition of subtypes in rural China over a 24-year period. Methods— In 1992, 14 920 residents were recruited to participate in the Tianjin Brain Study. Stroke events and all deaths were registered annually. We assessed the trends in incidence of first-ever stroke, including intracerebral hemorrhage and ischemic stroke, among adults aged 35 to 64 years during 1992 to 1999, 2000 to 2007, and 2008 to 2015. The annual proportion of change in stroke incidence was evaluated from 1992 to 2015. Results— The age-standardized incidence of first-ever stroke per 100 000 person-years increased significantly, from 122 in 1992 to 1999, to 215.8 in 2000 to 2007, to 471.8 in 2008 to 2015. The incidence of first-ever stroke increased annually by 11.9% overall (12.4% in men, 9.0% in women, 8.7% for intracerebral hemorrhage, and 10.7% for ischemic stroke; P<0.001). The greatest increases were observed in adults aged 55 to 64 years, with an annual increase of 11.6% for ischemic stroke (10.8% in men and 6.9% in women). However, the proportion of intracerebral hemorrhage has not changed over the past 24 years. Conclusions— In contrast with that in developed countries, the burden of stroke in China originates primarily from young and middle-aged adults. Thus, control of risk factors in this population is required to reduce the future burden of stroke in China.