Association between protein intake and changes in renal function among Japanese community-dwelling older people: The SONIC study.

AIM: The aim of this study was to clarify the association between dietary protein intake and decline in the estimated glomerular filtration rate (eGFR) among Japanese older adults. METHODS: We used the data of the Septuagenarians, Octogenarians and Nonagenarians Investigation with Centenarians (SONIC) study, an ongoing narrow-age range cohort study: 69-71 years, 79-81 years and 89-91 years. The outcome variable, change in eGFR, was estimated from serum creatinine measured at the baseline and 3-year follow up, and the exposure variable, protein intake, was calculated using the brief-type self-administered diet history questionnaire at the baseline. Associations between eGFR change and protein intake were determined by multiple linear regression analysis. RESULTS: The mean eGFR change per year was -1.89 mL/min/1.73 m2 . The mean protein intake was 1.50 g/kg/day. The results of this study showed that there was no significant association between protein or animal protein intake and change in eGFR per year in the entire population of participants, including the very elderly, but there was a significant positive association in those whose renal function fell into chronic kidney disease stage G3 or G4. CONCLUSIONS: Protein intake among community-dwelling older adults was not associated with lower eGFR, and for older chronic kidney disease patients, protein and animal protein intakes were more beneficial in maintaining eGFR. The results provide evidence that protein intake should not be restricted for older patients with chronic kidney disease, including the very elderly. Geriatr Gerontol Int 2022; 22: 286-291.

Association between uric acid and atherosclerosis in community-dwelling older people: The SONIC study.

AIM: The association between serum uric acid (UA) and atherosclerosis in old people is controversial. Therefore, in this study, we clarified this association by assessing serum UA and common carotid atherosclerosis examined by carotid ultrasound in community-dwelling older people in their 70s, 80s and 90s in the SONIC study. METHODS: A cross-sectional study was conducted involving 538 men and 577 women recruited from the community. The analysis was performed using serum UA as the explanatory variable and the maximum carotid intima-media thickness (max-CIMT) and mean-IMT as the dependent variables. The analysis was performed by multiple regression using traditional risk factors for atherosclerosis as adjustment variables. RESULTS: Analysis of the association between serum UA and IMT revealed a significant correlation only in women >70 years old. Max-CIMT (ß = 0.081, 95% CI = 0.026, 0.136; P = 0.004) and mean-IMT (ß = 0.015, 95% CI = 0.003, 0.029; P = 0.016) were significant. In the analysis of each age group, a significant correlation was only found in women in their 70s for mean-IMT (ß = 0.031, 95% CI = 0.008, 0.053; P = 0.008). CONCLUSION: In community-dwelling women aged about 70 years old, elevated serum UA may be an independent risk factor for IMT thickening as a surrogate marker for atherosclerosis. Geriatr Gerontol Int 2021; 21: 94-101.

Day-to-day blood pressure variability is associated with lower cognitive performance among the Japanese community-dwelling oldest-old population: the SONIC study.

Although high blood pressure (BP) and BP variability have been reported to be associated with cognitive impairment, few studies have investigated the association between home BP (HBP) and cognitive function in the oldest-old. The aim of this study was to evaluate whether the value of and the day-to-day variability in HBP was associated with cognitive function in a Japanese community-dwelling oldest-old population. Among 111 participants aged 85-87 years, cognitive function was assessed using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). HBP was measured two times every morning for a median of 30 days. The value of and variability in HBP were calculated as the average and coefficient of variation (CV) of the measurements, respectively. The associations of HBP variability with MoCA-J were examined using multiple linear regression models. Of 111 participants, 47.7% were men, and 64.0% were taking medications for hypertension. The mean HBP was 141.9 ± 14.8/72.2 ± 8.4 mmHg, and the mean CV of HBP was 6.7 ± 1.9/6.8 ± 2.4. The mean total MoCA-J score was 22.9 ± 3.5. The MoCA-J score was significantly lower with increasing CVs of both systolic BP (b = -0.36, p = 0.034) and diastolic BP (b = -0.26, p = 0.046) after adjustment for possible confounding factors. The value of HBP was not associated with MoCA-J. In the community-dwelling oldest-old population, higher day-to-day HBP variability, but not the value of HBP, was associated with cognitive impairment. When measuring HBP, attention should be paid not only to the values but also to their variations.

Association between long-term care and chronic and lifestyle-related disease modified by social profiles in community-dwelling people aged 80 and 90; SONIC study.

BACKGROUND: Chronic and lifestyle-related diseases and social status were reported to be associated with long-term care (LTC). The social factors should be treated as social sub-groups of which characteristics show social profiles. However, few previous studies considered that. The present study aimed to investigate the associations between LTC and chronic and lifestyle-related diseases, and whether the associations were modified by the social sub-groups in the community-dwelling elderly. METHOD: A cross-sectional study was conducted among 1004 community-dwelling participants aged 80 and 90. LTC was used as the outcome. Chronic and lifestyle-related diseases (i.e., stroke, heart disease, joint pain, osteoporosis, lung disease, cancer, hypertension, dyslipidemia, and diabetes) were used as the predictors. Education, household income, residential area, and support environment were analyzed by latent class analysis (LCA) to derive social profiles. We obtained odds ratios (ORs) of LTC from those diseases and tested interactions between those diseases and the social profiles by logistic regression analyses. RESULT: The participants were categorized into two sub-groups of social factors (n = 675 and 329) by LCA. Logistic regression analyses showed ORs (95% CI) of LTC were 4.69 (2.49, 8.71) from stroke, 2.22 (1.46, 3.38) from joint pain, 1.99 (1.22, 3.25) from osteoporosis, and 2.05 (1.22, 3.40) from cancer adjusting for the social sub-groups. There were no significant interactions between the social subgroups and those diseases in relation to LTC except for osteoporosis. CONCLUSION: The associations between LTC and chronic and lifestyle-related diseases were significant with adjusting for the social sub-groups, and not modified by that except osteoporosis.