Intergenerational 'mismatch' and adiposity in a developing population: the Guangzhou biobank cohort study

Both short and long sleep durations are associated with cognitive impairment among community-dwelling Chinese older adults

This study aims to examine the association between sleep duration and cognitive impairment in community-dwelling Chinese older adults.The associations between sleep duration and cognitive function have been widely studied across various age ranges but are of particular importance among older adults. However, there are inconsistent findings regarding the relationship between sleep duration and cognitive function in the literature.This study is an observational cross-sectional study. We analyzed data from 1115 Chinese individuals aged 60 and older from 3 Chinese communities (Beijing, Hefei, and Lanzhou). Cognitive impairment was defined as a Mini-Mental State Examination total score less than 24 points. Odds ratios (ORs) of associations were calculated and adjusted for potential confounders in logistic regression models.The prevalence of cognitive impairment was 25.7% (n = 287). Controlling for all demographic, lifestyle factors, and coexisting conditions, the adjusted OR for cognitive impairment was 2.54 (95% CI = 1.70-3.80) with <6 hours sleep and 2.39 (95% CI = 1.41-4.06) with >8 hours sleep.Both short and long sleep durations were related to worse cognitive function among community-dwelling Chinese elderly adults.

Socioeconomic status in childhood and obesity in adults: a population-based study

OBJECTIVE To test whether there is an association between socioeconomic status in childhood and measures of body mass index, waist circumference and the presence of overall and abdominal obesity in adult life. METHODS A cross-sectional analysis of a population-based cohort study, including a sample of adults (22-63 years old) living in Florianópolis, Southern Brazil. The socioeconomic status in childhood was analyzed through the education level of the participant's parents. Height, weight and waist circumference were measured by previously trained interviewers. Linear and logistic regressions with adjustment for confounding factors and stratification of data according to gender were used. RESULTS Of the 1,222 adults evaluated, 20.4% (95%CI 18.1-22.8) presented overall obesity and 24.8% (95%CI 22.4-27.4), abdominal obesity. The body mass index and waist circumference averages among women were, respectively, 1.2 kg/m2 (95%CI -2.3- -0.04) and 2.8 cm (95%CI -5.3- -0.2) lower among those with higher socioeconomic status in childhood. Among men, waist circumference was 3.9 cm (95%CI 1.0-6.8) higher in individuals with higher socioeconomic status in childhood. Regarding obesity, women of higher socioeconomic status in childhood had lower odds of abdominal obesity (OR = 0.56, 95%CI 0.34-0.90), and no such association was observed among men. CONCLUSIONS The socioeconomic status in childhood influences body mass index, waist circumference and obesity in adults, with a difference in the direction of association according to gender. The higher socioeconomic status among men and the lower socioeconomic status among women were associated with higher adiposity indicators.

The Association of Intergenerational Mismatch With Adiposity and Blood Pressure in Childhood and Adolescence

PURPOSE

An intergenerational "mismatch," a transition from limited to plentiful living conditions over generations, may increase cardiovascular disease risks. In a migrant population within a homogenous culture, we tested the hypothesis that an intergenerational mismatch in childhood living condition is associated with higher body mass index (BMI) and blood pressure in childhood and adolescence.

METHODS

We used data from 6,965 native born Chinese in Hong Kong (participated in "Children of 1997" birth cohort) and migrant Chinese born elsewhere in China in 1997 (N = 9,845). We classified children into those with intergenerational mismatch (child migrants or first-generation migrants) or those without (second+-generation migrants). Generalized estimating equations were used to examine the associations of migration status (child migrants, first-generation migrants or second+-generation migrants) with age- and sex-specific BMI z-score at 8-15 years and age-, sex-, and height-specific blood pressure z-score at 11-13 years, adjusted for sex, month of birth, and age.

RESULTS

Compared with second+-generation migrants, first-generation migrants had higher diastolic blood pressure z-score (.04, 95% confidence interval (CI) .02, .06) and BMI z-score (.12, 95% CI .06, .18), whereas child migrants had higher diastolic blood pressure z-score (.03, 95% CI .01, .05) regardless of age at migration and higher BMI z-score if they had migrated in infancy (.17, 95% CI .11, .23).

CONCLUSION

Different relations for blood pressure and BMI suggest that intergenerational mismatch and proximal exposures may have different impacts on adiposity and blood pressure.

Changes in adiposity in an older Chinese population in rapid economic transition

OBJECTIVE

To examine the changes in body mass index (BMI) and waist circumference (WC) in Guangzhou, South China, which is probably experiencing the most rapid economic transition in history.

METHODS

In this study, 17,786 Chinese aged 50+ years were recruited from 2003 to 2008 and followed up until 2012. BMI and WC were measured at two time points.

RESULTS

During the mean follow-up of 3.6 years (median = 3, interquartile = 1), age-adjusted mean BMI increased only slightly. By contrast, mean WC increased sharply by 0.94 cm (95% confidence interval 0.93-0.94) annually in men and 1.29 cm (1.28-1.29) annually in women. In 77% of women and 69% of men, WC increased, and among them, the mean annual increase was 2.01 cm and 1.70 cm, respectively. Among healthy, never-smoking participants, the incidence of central obesity was 29.0% (36.4% in women and 14.2% in men). The incidence of general obesity was 1.9% and was similarly low in both men and women (2.1% vs. 1.8%). Conversely, 20.3% of individuals with general obesity became nonobese, and 12.8% of individuals with central obesity returned to normal.

CONCLUSIONS

Central obesity has risen sharply in this cohort. Such increases may have been greatly underestimated previously and should form the basis of an even stronger warning for regions undergoing economic transitions in China and elsewhere.

Social Patterning in Adiposity in Adolescence: Prospective Observations from the Chinese Birth Cohort ''Children of 1997''

INTRODUCTION

Low early life socio-economic position is more strongly associated with adiposity among women than men. We examined whether the sex difference of social patterning in general and central adiposity exists before adulthood.

METHODS

In Hong Kong's "Children of 1997" birth cohort, we used multivariable regression to examine the association of parental education, a marker of early life socio-economic position, with body mass index (BMI) (n = 7252, 88% follow-up) and waist-height ratio (n = 5636, 68% follow-up), at 14 years.

RESULTS

Parental education of Grade 9 or below, compared to Grade 12 or above, was associated with higher waist-height ratio z-score particularly in girls (0.30, 95% confidence interval (CI) 0.19, 0.41) compared to boys (0.12, 95% CI 0.02, 0.22) (p for sex interaction = 0.02). Lower parental education was associated with greater BMI z-score in adolescents of locally born mothers, but not adolescents of migrant mothers, with no difference by sex.

CONCLUSIONS

Different social patterning in different markers of adiposity may imply different sociological and biological mediating pathways. A stronger association between low early life socio-economic position and waist-height ratio in adolescent girls may indicate sex-specific influences of SEP related early life exposures on central adiposity.

Life-course origins of social inequalities in adult immune cell markers of inflammation in a developing southern Chinese population: the Guangzhou Biobank Cohort Study

BACKGROUND

Socioeconomic position (SEP) throughout life is associated with cardiovascular disease, though the mechanisms linking these two are unclear. It is also unclear whether there are critical periods in the life course when exposure to better socioeconomic conditions confers advantages or whether SEP exposures accumulate across the whole life course. Inflammation may be a mechanism linking socioeconomic position (SEP) with cardiovascular disease. In a large sample of older residents of Guangzhou, in southern China, we examined the association of life course SEP with inflammation.

METHODS

In baseline data on 9,981 adults (≥ 50 years old) from the Guangzhou Biobank Cohort Study (2006-08), we used multivariable linear regression and model fit to assess the associations of life course SEP at four stages (childhood, early adult, late adult and current) with white blood, granulocyte and lymphocyte cell counts.

RESULTS

A model including SEP at all four life stages best explained the association of life course SEP with white blood and granulocyte cell count for men and women, with early adult SEP (education) making the largest contribution. A critical period model best explained the association of life course SEP with lymphocyte count, with sex-specific associations. Early adult SEP was negatively associated with lymphocytes for women.

CONCLUSIONS

Low SEP throughout life may negatively impact late adult immune-inflammatory status. However, some aspects of immune-inflammatory status may be sensitive to earlier exposures, with sex-specific associations. The findings were compatible with the hypothesis that in a developing population, upregulation of the gonadotropic axis with economic development may obscure the normally protective effects of social advantage for men.

The utility of collaborative biobanks for cardiovascular research

Differences between animal and human atherosclerosis have led to the requirement for clinical data, imaging information and biological material from large numbers of patients and healthy persons. Where such "biobanks" exist, they have been fruitful sources for genomewide association, diagnostic accuracy, ethnicity, and risk stratification cohort studies. In addition once established, they attract funding for future projects. Biobanks require a network of medical contributors, secure storage facilities, bioinformatics expertise, database managers, and ethical working practices to function optimally. There is the opportunity for collaboration between individual biobanks to further amplify the advantages afforded.

Intergenerational influences on diabetes in a developing population: the Guangzhou Biobank Cohort Study

OBJECTIVES

Intergenerational "mismatch" and/or growth conditions may be relevant to the epidemic of diabetes in developing populations. In a rapidly developing southern Chinese population, we tested whether maternal environment, proxied by maternal literacy, or family socio-economic position (SEP), proxied by paternal literacy, were associated with fasting glucose and diabetes. To assess if intergenerational mismatch contributed, we tested whether the associations varied by life course SEP.

METHODS

In 19,818 older (≥50 years) adults from the Guangzhou Biobank Cohort Study (phases 2 and 3), we used censored and logistic regression to assess the associations of maternal and paternal literacy with fasting glucose, elevated fasting glucose and diabetes and whether these associations varied by sex, age or life course SEP.

RESULTS

Maternal, but not paternal, literacy was negatively associated with fasting plasma glucose (β-coefficient -0.06 mmol/l, 95% confidence interval (CI) -0.11 to -0.01) and elevated fasting glucose (odds ratio (OR) 0.92, 95% CI 0.86-0.99) adjusted for age, sex, study phase, life course SEP, childhood growth, adiposity, number of offspring, and birth order. Associations of maternal and paternal literacy with fasting glucose, elevated fasting glucose and diabetes did not vary by sex, age or life course SEP.

CONCLUSION

Offspring of literate mothers had lower risk for impaired glucose tolerance than offspring of illiterate mothers. Being raised by literate mothers may increase the likelihood of children with higher SEP and lower long-term disease risk, or better maternal conditions over generations may be associated with lower fasting glucose.

Short or long sleep duration is associated with memory impairment in older Chinese: the Guangzhou Biobank Cohort Study

STUDY OBJECTIVES

To examine the association between sleep-related factors and memory impairment.

DESIGN

Cross-sectional study

SETTING

Community-based study in Guangzhou, China.

PARTICIPANTS

28,670 older Chinese (20,776 women and 7,894 men) aged 50 to 85 years.

MEASUREMENTS AND RESULTS

Demographic and socioeconomic data, sleep-related factors, and cognitive function were collected by face-to-face interview. Potential confounders, such as employment and occupational status, smoking, alcohol and tea use, physical activity, self-rated health, anthropometry, blood pressure, and fasting plasma glucose and lipids were measured. After adjusting for multiple potential confounders, an inverted U-shaped association between sleep duration and delayed word recall test (DWRT) score, a validated measure of memory impairment, was found, with 7 to 8 h of habitual sleep duration showing the highest score (P-values for trend from 3 to 7 h and from 7 to ≥ 10 h were all ≤ 0.001). Compared to sleep duration of 7 h, the adjusted odds ratio for memory impairment from the sleep duration of 3 to 4 or ≥ 10 h was 1.29 (95% confidence interval 1.07-1.56) and 1.52 (1.25-1.86), respectively. Subjects with daily napping, morning tiredness, or insomnia had significantly lower DWRT scores than those without (P ranged from < 0.001 to 0.01).

CONCLUSIONS

Short or long sleep duration was an important sleep-related factor independently associated with memory impairment and may be a useful marker for increased risk of cognitive impairment in older people.