Metabolic obesity phenotypes and all-cause mortality among the Chinese oldest-old population: a prospective cohort study.

BACKGROUND: The obesity paradox has been reported among older adults. However, whether the favorable effect of obesity is dependent on metabolic status remains largely unknown. We aimed to explore the association of metabolic obesity phenotypes and their changes with all-cause mortality among the Chinese oldest-old population. METHODS: This prospective cohort study included 1207 Chinese oldest old (mean age: 91.8 years). Metabolic obesity phenotypes were determined by central obesity and metabolic status, and participants were classified into metabolically healthy obesity (MHO), metabolically unhealthy obesity (MUO), metabolically healthy non-obesity (MHN), and metabolically unhealthy non-obesity (MUN). The hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated by Cox regression models. RESULTS: During 5.3 years of follow-up, 640 deaths were documented. Compared with non-obesity, obesity was associated with a decreased mortality risk among participants with metabolically healthy (HR, 0.75; 95% CI, 0.63-0.91) while this association was insignificant among metabolically unhealthy. Compared to MHO, MHN (HR, 1.27; 95% CI, 1.06-1.53) and MUN (HR, 1.49; 95% CI, 1.10-2.02) were significantly associated with an increased mortality risk. Compared to those with stable MHO, those transited from MHO to MUO demonstrated a higher mortality risk (HR, 1.81; 95% CI, 1.06-3.11). CONCLUSIONS: MHO predicts better survival among the Chinese oldest-old population. These findings suggest that ensuring optimal management of metabolic health is beneficial and taking caution in weight loss based on the individual body weight for the metabolically healthy oldest-old adults.

Long-term air pollution exposure, habitual physical activity, and incident chronic kidney disease.

Both air pollution and physical inactivity contribute to the increased risk of incident chronic kidney disease (CKD). However, the detrimental effects of air pollution exposure could be augmented by an elevated intake of air pollutants during exercise. In the present study, we analyzed 367,978 participants who were CKD-free at baseline (2006-2010) based on the UK Biobank. Air pollutants included fine particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), and nitrogen oxides (NOX). Physical activity (PA) was obtained by the self-reported questionnaire. Using Cox proportional hazards models, hazard ratios (HRs) for incident CKD related to air pollution, PA, and incident CKD were evaluated. During a median of 12.4 years of follow-up, 14,191 incident CKD events were documented. High PM2.5, PM10, NO2, and NOX increased CKD risks by 11 %, 15 %, 14 %, and 12 %, respectively, while moderate and high PA reduced CKD risks by 18 % and 22 %, respectively. Participants with high PA and low air pollution exposure had 29 %, 31 %, 30 %, and 30 % risks of incident CKD than those with low PA and high air pollution exposure for the four air pollutants, with multivariable-adjusted HRs of 0.71 (95 % confidence intervals [CI]: 0.65-0.76) for PM2.5, 0.69 (95 % CI: 0.64-0.75) for PM10, 0.70 (95 % CI: 0.64-0.75) for NO2, and 0.70 (95 % CI: 0.64-0.75) for NOX. No clear interactions were observed between each air pollutant exposure and PA (all P for interaction > 0.05). The findings that reducing air pollution exposure and increasing PA were both independently correlated with a diminished risk of incident CKD suggest that PA could be targeted to prevent CKD generally regardless of air pollution levels. Further research is needed in areas polluted moderately and severely to examine our findings.

Serum 25-hydroxyvitamin D concentrations and colorectal cancer incidence in adults with type 2 diabetes.

BACKGROUND: To examine the association of serum 25-hydroxyvitamin D (25[OH]D) with colorectal cancer (CRC) risk in adults with type 2 diabetes (T2D). METHODS: Using UK Biobank data, this study included 18,453 adults with T2D. Serum 25(OH)D concentrations were determined by the chemiluminescent immunoassay method. A Cox proportional hazards model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for CRC outcomes. RESULTS: During a median follow-up of 8.8 years, there were 284 incident CRC cases. Compared with adults with serum 25(OH)D concentrations <25.0 nmol/L, the adjusted HRs (95% CIs) for lower to higher serum 25(OH)D concentrations (25.0 to <50.0, 50.0 to <75.0, and ≥75.0 nmol/L) were 0.61 (0.46-0.82), 0.50 (0.34-0.74), and 0.53 (0.30-0.94), respectively (Ptrend = 0.001). The risk of CRC decreased by 19.0% for per 1-SD increment in serum 25(OH)D concentrations. A nonlinear association of serum 25(OH)D concentrations with CRC risk was observed using a restricted cubic spline analysis (P nonlinearity = 0.002). CONCLUSIONS: Higher serum 25(OH)D concentrations were significantly and nonlinearly associated with a lower risk of CRC. These findings highlight the potential benefits of maintaining adequate vitamin D levels in CRC prevention among adults with T2D.

Association of Night Shifts and Lifestyle Risks With Incident Dementia.

BACKGROUND: Little is known about the combined relationship between night shifts and lifestyle risks with incident dementia or their potential interactions. To evaluate the association of night shifts and lifestyle risks with incident dementia and further analyze their interactions. METHODS: A total of 276 059 participants were included in this study from the UK Biobank cohort. Cox proportional hazards models were used to investigate the combined association of night shifts and lifestyle risks with incident dementia. RESULTS: Participants with always night shifts and 3 or 4 unhealthy lifestyle factors had the highest risk of incident all-cause dementia (hazard ratio: 3.15, 95% confidence interval [CI]: 1.74-5.69). An additive interaction was found between night shifts and lifestyle risks for incident all-cause dementia (p < .001), with a relative excess risk due to the interaction of 0.14 (95% CI: 0.11-0.45). The attributable proportions of the combined effect on the incidence of all-cause dementia were 22.6% (95% CI: 20.91%-26.75%) for night shift work, 65.0% (95% CI: 63.12%-69.80%) for unhealthy lifestyle factors, and 12.1% (95% CI: 8.67%-18.04%) for their interaction. CONCLUSIONS: Both night shifts and lifestyle risks were associated with a higher risk of incident dementia. The combined impact was higher than the increase in the risks related to each single factor. Our results indicated that most incident dementia cases might be prevented by a healthy lifestyle, and the benefits would be greater among night shift workers. Further studies are needed to confirm our results and explore the underlying mechanisms.

Dietary diversity and frailty among older Chinese people: evidence from the Chinese Longitudinal Healthy Longevity Study.

BACKGROUND: Dietary diversity is widely advocated as a means to promote health, but little is known regarding whether the beneficial effects still apply in older adults. OBJECTIVE: To examine the association between the dietary diversity score (DDS) and frailty among older Chinese adults. METHODS: A total of 13,721 adults aged ≥65 y without frailty at baseline were enrolled. The DDS at baseline was constructed based on 9 items of a food frequency questionnaire. We used 39 self-reported health items to construct a frailty index (FI), with FI ≥ 0.25 indicating frailty. Cox models with restricted cubic splines were used to evaluate the dose-response relationships of DDS (continuous) with frailty. In addition, Cox proportional hazard models were used to examine the association between DDS (categorized as scores ≤4, 5-6, 7, and ≥8) and frailty. RESULTS: During the mean follow-up of 5.94 y, 5250 participants met the criteria for frailty. Each 1-unit increase in DDS corresponded to a 5% lower risk of frailty (hazard ratio [HR]; 0.95; 95% CI: 0.94, 0.97]. Compared with participants with DDS ≤4 points, those with a DDS of 5-6, 7, and ≥8 points exhibited a lower frailty risk, with HRs of 0.79 (95% CI: 0.71, 0.87), 0.75 (95% CI: 0.68, 0.83), and 0.74 (95% CI: 0.67, 0.81), respectively (P-trend < 0.001). Protein-rich food items, such as meat; eggs; and beans, were associated with protective effects against frailty. In addition, a significant association was observed between higher consumption of 2 high-frequency foods, tea and fruits, and lower risk of frailty. CONCLUSIONS: A higher DDS was associated with a lower risk of frailty among older Chinese adults. This study highlights the importance of a diverse diet as a potential modifiable behavioral factor for preventing frailty in older Chinese adults.

Habitual fish oil supplementation and incident chronic obstructive pulmonary disease: Data from a prospective cohort study.

BACKGROUND: Fish oil is one of the most popular supplements in the UK and other developed countries. However, the relationship between fish oil use and chronic obstructive pulmonary disease (COPD) is unclear. OBJECTIVE: To prospectively examine the association of habitual fish oil supplementation with incident COPD risk and to evaluate potential effect modification by genetic predisposition. METHODS: This study included 484,414 participants (mean and standard deviation [SD] age: 56.5 [8.1] years) from the UK Biobank who completed a touchscreen questionnaire on habitual fish oil supplement use between 2006 and 2010 and were followed up through 2018. Cox regression models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) with adjustment for sociodemographic and lifestyle behaviours, health conditions, and other potential confounding factors. A weighted genetic risk score (GRS) for COPD was derived from 112 validated single nucleotide polymorphisms. RESULTS: During a median follow-up of 9.0 years, 8860 incident COPD events were recorded. A total of 31.4% (152,230) of the study participants reported habitual fish oil supplementation at baseline. Habitual fish oil supplementation was significantly associated with a lower risk of incident COPD (adjusted HR: 0.88; 95% CI: 0.84-0.93). The association with COPD did not differ by GRS strata (P for interaction = 0.880). The results from subgroup and sensitivity analyses supported the robustness of our findings. CONCLUSIONS: Our findings suggest that habitual fish oil supplementation is associated with a lower risk of incident COPD, irrespective of genetic predisposition.

THz imaging technique for nondestructive analysis of debonding defects in ceramic matrix composites based on multiple echoes and feature fusion.

We propose a THz nondestructive analysis method based on multiple echoes and feature fusion. Conventionally, it is difficult to identify the debonding defects of the glue layer (II) due to the thin adhesive layer. To this end, a THz propagation model is established, and a quantitative method for determining the thickness of debonding defects based on multiple echoes is presented. The measurement error for preset defect thickness of 500 µm was 4%. Further, for determining the area of debonding defects, a feature fusion imaging algorithm is proposed to realize the lateral recognition of defects and quantitative analysis is used to improve the recognition ability of defects.