Influence of Diabetes Family History on the Associations of Combined Genetic and Lifestyle Risks with Diabetes in the Tohoku Medical Megabank Community-Based Cohort Study.

AIM: The influence of family history of diabetes, probably reflecting genetic and lifestyle factors, on the association of combined genetic and lifestyle risks with diabetes is unknown. We examined these associations. METHODS: This cross-sectional study included 9,681 participants in the Tohoku Medical Megabank Community-based Cohort Study. A lifestyle score, which was categorized into ideal, intermediate, and poor lifestyles, was given. Family history was obtained through a self-reported questionnaire. A polygenic risk score (PRS) was constructed in the target data (n=1,936) using publicly available genome-wide association study summary statistics from BioBank Japan. For test data (n=7,745), we evaluated PRS performance and examined the associations of combined family history and genetic and lifestyle risks with diabetes. Diabetes was defined as non-fasting blood glucose ≥ 200 mmHg, HbA1c ≥ 6.5%, and/or self-reported diabetes treatment. RESULTS: In test data, 467 (6.0%) participants had diabetes. Compared with a low genetic risk and an ideal lifestyle without a family history, the odds ratio (OR) was 3.73 (95% confidence interval [CI], 1.92-7.00) for a lower genetic risk and a poor lifestyle without a family history. Family history was significantly associated with diabetes (OR, 3.58 [95% CI, 1.73-6.98]), even in those with a low genetic risk and an ideal lifestyle. Even among participants who had an ideal lifestyle without a family history, a high genetic risk was associated with diabetes (OR, 2.49 [95% CI, 1.65-3.85]). Adding PRS to family history and conventional lifestyle risk factors improved the prediction ability for diabetes. CONCLUSIONS: Our findings support the notion that a healthy lifestyle is important to prevent diabetes regardless of genetic risk.

Association of Central Blood Pressure and Carotid Intima Media Thickness with New-Onset Hypertension in People with High Normal Blood Pressure.

AIM: People with high normal blood pressure (BP) have a higher risk of cardiovascular events than those with normal BP; therefore, progression to hypertension (HT) should be prevented. We aimed to assess the HT risk using central BP and carotid intima media thickness (CIMT) in people with high normal BP. METHODS: This prospective cohort study used the Tohoku Medical Megabank Community-Based Project Cohort Study (conducted from 2013 in Miyagi Prefecture in Japan). The participants had a high normal BP, defined as a systolic BP of 120-139 mmHg and diastolic BP ＜90 mmHg using brachial BP measurement during the baseline survey. The outcome was new-onset HT during the secondary survey, conducted four years after the baseline survey. RESULTS: Overall, 4,021 participants with high normal BP during the baseline survey, with an average age of 58.7 years, were included; 1,030 (26%) were diagnosed with new-onset HT during the secondary survey, 3.5±0.7 years after the baseline survey. The multivariable odds ratio (95% confidence interval) for HT in the highest versus lowest quartile of central BP was 1.7 (1.2-2.4, p=0.0030), and that of CIMT was 1.8 (1.4-2.4, p＜0.001). Subgroup analysis according to age (＜60 and ≥ 60 years) and sex revealed that the central BP was influential in groups with younger age and female individuals; CIMT was influential in all groups. CONCLUSIONS: Higher central BP and thicker CIMT at the baseline were correlated with new-onset HT in individuals with high normal BP, independent of brachial systolic BP and other cardiovascular risk factors.

Associations between the Combined Fat Mass Index and Fat-Free Mass Index with Carotid Intima-Media Thickness in a Japanese Population: The Tohoku Medical Megabank Community-Based Cohort Study.

AIM: Although many epidemiological studies have shown that obesity assessed by body mass index is associated with carotid intima-media thickness (cIMT), few studies have evaluated fat-free mass, which is a component of body composition. We investigated the associations between the combined fat mass index (FMI) and fat-free mass index (FFMI) with cIMT. METHODS: We conducted a cross-sectional study of 3,873 men and 9,112 women aged 20 years or older who lived in Miyagi prefecture, Japan. The FMI and FFMI were calculated as fat mass and fat-free mass divided by height squared, respectively. The indices were classified into sex-specific quartiles and were combined into 16 groups. The maximum common carotid artery was measured using high-resolution B-mode ultrasound. An analysis of covariance was used to assess associations between the combined FMI and FFMI with cIMT adjusted for age and smoking status. The linear trend test was conducted by stratifying the FMI and FFMI, scoring the categories from 1 (lowest) to 4 (highest), and entering the number as a continuous term in the regression model. RESULTS: In multivariable models, a higher FMI was not related to higher cIMT in men and women in most FFMI subgroups. Conversely, a higher FFMI was related to higher cIMT in all FMI subgroups (p＜0.001 for linear trend). CONCLUSIONS: FMI was not associated with cIMT in most FFMI subgroups. Conversely, FFMI was positively associated with cIMT independently of FMI.