Objectives: The aim of this study is to identify the relationship between diabetes status including characteristics of diabetes and cognition among the middle-aged and elderly population (≥45 years) in China. Methods: A sample of 8535 people who participated in the China Health and Retirement Longitudinal Study (CHARLS) from June 2011 to March 2012 was analyzed. Two cognitive domains including episodic memory and executive function were measured through questionnaires. People were classified into four groups: no diabetes, controlled diabetes, untreated diabetes, treated but uncontrolled diabetes. Weighted multiple regression model was conducted to explore the association between diabetes and cognition in full sample as well as three different age groups (45–59, 60–74, ≥75). Adjustments were made for demographics and cardiovascular risk factors. Results: After adjusting several covariates, untreated diabetes (β = −0.192, p < 0.05) was significantly associated with episodic memory. In the age group of 45–69 years, untreated diabetes (β = −0.471, p < 0.05) and HbA1c level (β = −0.074, p < 0.05) were significantly associated with episodic memory. When adjusting for cardiovascular risk factors, all correlations were non-significant. Conclusion: The cross-sectional study suggests that untreated diabetes and HbA1c are the potential risk factor for cognitive impairment, and these associations are more significant in the age group of 45–59 years old. Cardiovascular factors are important mediating factors in the pathway between diabetes and cognitive impairment. More longitudinal studies are needed to confirm these associations.

Fish and seafood are excellent sources of nutrients such as omega-3 fatty acids, Vitamin D, and selenium. The aims of this study were to examine the pattern of seafood consumption among Canadians and determine their contribution to intakes of energy and nutrients. Day-1 24-h dietary recalls data collected from a national survey, the Canadian Community Health Survey—Nutrition in 2004 and 2015, were used to estimate food and nutrient intakes among Canadians. Seafood was classified according to the Bureau of Nutritional Sciences food list. Descriptive statistics were used to calculate the consumption rate and the average consumption amount of seafood by different age groups and sociodemographic characteristics. Population ratios were used to assess the contribution of seafood to the total intake of energy and nutrients. The overall consumption rate of seafood was around 17%, and the rate was similar between males and females, and slightly higher in 2015 (17.71%) compared to 2004 (16.38%). The average portion size is approximately 100 g, which translates into a ≈36 kg annual intake among the consumers and ≈6.2 kg per capita consumption. Adults (especially 30 years and above), Asians, individuals who were married, and with post-secondary education were more likely to consume seafood. Salmon, tuna, shrimp, cod, and crab were the most frequently consumed seafood in Canada, the consumption rate of which all increased from 2004 to 2015. Seafood provided up to 75% of n-3 PUFAs, 18% of Vitamin D, 19% Vitamin B12, 6% of niacin, and 4% of Vitamin B6 from all food sources. Seafood consumers had a healthier diet, as seafood consumption was related to a higher intake of key nutrients and a lower intake of total sugar and saturated fatty acids. Therefore, fish consumption should be promoted among Canadians.

We previously studied the association between fish consumption and prevalence of type 2 diabetes (T2D) in Manitoba and Ontario First Nations (FNs), Canada and found different results. In this study, we used a difference in difference model to analyze the data. Dietary and health data from the First Nations Food Nutrition and Environment Study, a cross-sectional study of 706 Manitoba and 1429 Ontario FNs were analyzed. The consumption of fish was estimated using a food frequency questionnaire. Fish samples were analyzed for dichloro diphenyldichloro ethylene (DDE) and polychlorinated biphenyls (PCBs) content. Difference in difference model results showed that persistent organic pollutant (POP) exposure was positively associated with T2D in a dose-response manner. Stronger positive associations were found among females (OR = 14.96 (3.72–60.11)) than in males (OR = 2.85 (1.14–8.04)). The breakpoints for DDE and PCB intake were 2.11 ng/kg/day and 1.47 ng/kg/day, respectively. Each further 1 ng/kg/day increase in DDE and PCB intake increased the risk of T2D with ORs 2.29 (1.26–4.17) and 1.44 (1.09–1.89), respectively. Our findings suggest that the balance of risk and benefits associated with fish consumption is highly dependent on the regional POP concentrations in fish.

Disease incidence and prevalence are both core indicators of population health. Incidence is generally not as readily accessible as prevalence. Cohort studies and electronic health record systems are two major way to estimate disease incidence. The former is time-consuming and expensive; the latter is not available in most developing countries. Alternatively, mathematical models could be used to estimate disease incidence from prevalence. We proposed and validated a method to estimate the age-standardized incidence of cardiovascular disease (CVD), with prevalence data from successive surveys and mortality data from empirical studies. Hallett’s method designed for estimating HIV infections in Africa was modified to estimate the incidence of myocardial infarction (MI) in the U.S. population and incidence of heart disease in the Canadian population. Model-derived estimates were in close agreement with observed incidence from cohort studies and population surveillance systems. This method correctly captured the trend in incidence given sufficient waves of cross-sectional surveys. The estimated MI declining rate in the U.S. population was in accordance with the literature. This method was superior to closed cohort, in terms of the estimating trend of population cardiovascular disease incidence. It is possible to estimate CVD incidence accurately at the population level from cross-sectional prevalence data. This method has the potential to be used for age- and sex- specific incidence estimates, or to be expanded to other chronic conditions.