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

Genetic loci, rs17817449 and rs6567160, known for obesity and the risk of stroke events among middle-aged and older Chinese people

BACKGROUND

Fat Mass and Obesity-Associated (FTO) and the Melanocortin-4 Receptor (MC4R) genes are strongly associated with obesity, an established risk factor for stroke. We aimed to assess the associations between rs17817449 at the FTO and rs6567160 at the MC4R and the risk of stroke events in middle-aged and older Chinese people.

MATERIALS AND METHODS

Study data were obtained from the Guangzhou Biobank Cohort Study; a total of 148 participants with a self-reported history of stroke and an equal volume of age- and sex-matched participants were selected as the cases and the controls in a case-control study; a total of 13,967 participants at the first follow-up and all participants with fatal stroke (up to April 2021) were included in a retrospective cohort study. Conditional logistic regression and the Cox proportional hazards regression analyses were used to assess the associations of the two genetic loci with the risk of stroke events.

RESULTS

After adjusting for age, sex, education, job, smoking, alcohol consumption, body mass index, physical activity, hypertension, diabetes, and dyslipidemia, rs17817449 and rs6567160 shared minor alleles G and C, respectively, in the case-control analyses. The genotypes GG+GT of rs17817449 at the FTO were significantly associated with a decreased risk of fatal stroke occurrence, with fatal all strokes having an adjusted hazard ratio (aHR) of 0.71 (95% confidence intervals (CI) 0.52-0.97, P = 0.04) and fatal ischemic stroke having an aHR of 0.64 (95% CI 0.41-1.00, P = 0.05), when the genotype TT was taken as a reference and a series of multiplicities were adjusted; the risk of fatal all strokes was lowered by dyslipidemia (aHR = 0.63, 95% CI 0.39-1.00, P = 0.05) and non-diabetes (aHR = 0.68, 95% CI 0.46-0.99, P = 0.049) in the retrospective cohort analyses. Significances were observed neither in the associations between rs6567160 and the risk of stroke events nor in an interaction between rs17817449 and rs6567160 in the two-stage analyses.

CONCLUSION

The G allele of rs17817449 at the FTO, not rs6567160 at the MC4R, was associated with a decreased risk of fatal stroke occurrence; its functional role in stroke should be explored in relatively healthy middle-aged to older Chinese people.

Socioeconomic status and prevalence of type 2 diabetes in mainland China, Hong Kong and Taiwan: a systematic review

BACKGROUND

China is estimated to have had the largest number of people with diabetes in the world in 2015, with extrapolation of existing data suggesting that this situation will continue until at least 2030. Type 2 diabetes has been reported to be more prevalent among people with low socioeconomic status (SES) in high-income countries, whereas the opposite pattern has been found in studies from low- and middle-income countries. We conducted a systematic review to describe the cross-sectional association between SES and prevalence of type 2 diabetes in Chinese in mainland China, Hong Kong and Taiwan.

METHODS

We conducted a systematic literature search in Medline, Embase and Global Health electronic databases for English language studies reporting prevalence or odds ratio for type 2 diabetes in a Chinese population for different SES groups measured by education, income and occupation. We appraised the quality of included studies using a modified Newcastle-Ottawa Scale. Heterogeneity of studies precluded meta-analyses, therefore we summarized study results using a narrative synthesis.

RESULTS

Thirty-three studies met the inclusion criteria and were included in the systematic review. The association between education, income and occupation and type 2 diabetes was reported by 27, 19 and 12 studies, respectively. Most, but not all, studies reported an inverse association between education and type 2 diabetes, with odds ratios (OR) and 95% confidence interval (CI) ranging from 0.39 (CI not reported) to 1.52 (95% CI 0.91 - 2.54) for the highest compared to the lowest education level. The association between income and type 2 diabetes was inconsistent between studies. Only a small number of studies identified a significant association between occupation and type 2 diabetes. Retired people and people working in white collar jobs were reported to have a higher risk of type 2 diabetes than other occupational groups even after adjusting for age.

CONCLUSIONS

This first systematic review of the association between individual SES and prevalence of type 2 diabetes in China found that low education is probably associated with an increased prevalence of type 2 diabetes, while the association between income and occupation and type 2 diabetes is unclear.

The Relationship between Metabolic Syndrome and Childhood Maternal Education Level, Job Status Findings from the Korean National Health and Nutrition Examination, 2007-2009

BACKGROUND

Childhood socioeconomic status (SES) is known to affect cardio-metabolic disease risk. However, the relationship between childhood SES and metabolic syndrome (MetS) remains uncertain. Therefore, we investigated the relationship between childhood SES, as measured by maternal education and occupational status and adult-onset MetS in the Korean population.

METHODS

We examined the association between childhood SES, as measured by maternal education level and occupational status during an individual's childhood, and MetS in Korean adults aged 20 to 79 years who participated in the 2007-2009 Korean National Health Examination and Nutrition Survey. The components of MetS, including waist circumference, fasting glucose, lipid profiles, and blood pressure, were measured. Adjusted odds ratios (ORs) for MetS were calculated using multiple logistic regression models.

RESULTS

Significant differences in the association between maternal education level, occupational status, and MetS were found between males and females. In females, the adjusted MetS OR for the highest maternal education quartile relative to the lowest quartile was 0.46 (0.21-0.99). Similarly, in females, the adjusted OR for individuals whose mothers worked when they were children relative to those whose mothers did not work was 1.23 (1.04-1.44). In males, no significant associations between maternal education, maternal occupational status, and MetS were found.

CONCLUSION

We found independent, positive associations between maternal education and occupational status and MetS in Korean females. These findings suggest that public health education targeting MetS prevention should be considered, especially among children with less opportunity for maternal support.

Pubertal muscle mass and diabetes markers in Chinese adolescents

OBJECTIVES

Diabetes is common in China despite a relatively nonobese population. We hypothesized that testosterone driven muscle mass acquisition at puberty may be relevant. We examined the associations of testosterone with muscle mass and of muscle mass with fasting glucose in Chinese adolescents.

METHODS

In 40 adolescents (20 boys and 20 girls, age 12.9 ± 0.1 years) from Hong Kong's "Children of 1997" birth cohort, we used multivariable linear regression to assess adjusted associations of testosterone and fasting glucose (from a morning blood sample) with muscle and fat mass from a dual-energy X-ray absorptiometry scan.

RESULTS

Testosterone was positively associated with muscle mass (0.05 kg, 95% confidence interval (CI) 0.01 to 0.09, per pg/ml testosterone). Muscle mass was associated with lower glucose (-0.04 mmol/l, 95% CI -0.08 to -0.01 per kg muscle mass) adjusted for sex and fat mass.

CONCLUSIONS

Environmentally driven muscle mass acquisition at puberty could influence diabetes.