Association of physical activity and appetite with visual function related to driving competence in older adults

Interaction between visual impairment and subjective cognitive complaints on physical activity impairment in U.S. older adults: NHANES 2005-2008

BACKGROUND/AIM

To investigate the independent relationships of visual impairment (VI) and Subjective cognitive complaints (SCC) with physical function impairment (PFI) and the interaction effect between VI and SCC on PFI in American older adults.

METHODS

The data of this cross-sectional study was obtained from the 2005-2008 National Health and Examination Survey (NHANES) conducted in the United States. The VI criterion included both subjective self-reported eyesight conditions and objective visual acuity test results. The self-reported questionnaires were utilized to determine PFI and SCC. According to the survey design of NHANS, original data were weighted to produce nationally representative estimates. Both the unweighted original data and weighted estimates underwent analysis. Crude and adjusted logistic models were employed to assess the pairwise associations among VI, SCC, and PFI. To assess the interactive effect, measures such as the relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP), and synergy index (S) were calculated.

RESULTS

A total of 2,710 subjects (weighted n = 38,966,687) aged 60 years or older were included. Compared with subjects without subjective visual impairment (SVI), those with SVI had a significant positive association with PFI [weighted OR (95%CI): 3.11 (2.25, 4.31)]. After multi-variable adjusting, the relationship remained significant [weighted OR (95%CI): 1.90 (1.32, 2.72)]. Similarly, those with objective visual impairment (OVI) were positively associated with the risk of PFI in the crude model [weighted OR (95%CI): 2.35 (1.53, 3.61)] and adjusted model [weighted OR (95%CI): 1.84 (1.07, 3.17)]. Moreover, we found the association of SCC with an increased risk of FPI [crude weighted OR (95%CI): 5.02 (3.40, 7.40); adjusted weighted OR (95%CI): 3.29 (2.01, 5.38)]. Ultimately, the additive interaction showed there was a significant positive interaction term between SVI and SCC on PFI, while OVI and SCC did not.

CONCLUSION

Both VI and SCC were significantly associated with PFI in elder adults. Besides, there was a significant synergistic interaction between SVI and SCC on PFI, which indicated the improvement of SVI and SCC may be beneficial for the prevention of PFI. For the elderly, especially those with multiple disabilities, comprehensive and targeted approaches are imperative to foster their overall well-being and health.

BOLD signal response in primary visual cortex to flickering checkerboard increases with stimulus temporal frequency in older adults

Many older adults have difficulty seeing brief visual stimuli which younger adults can easily recognize. The primary visual cortex (V1) may induce this difficulty. However, in neuroimaging studies, the V1 response change to the increase of temporal frequency of visual stimulus in older adults was unclear. Here we investigated the association between the temporal frequency of flickering stimuli and the BOLD activity within V1 in older adults, using surface-based fMRI analysis. The fMRI data from 29 healthy older participants stimulated by contrast-reversing checkerboard at temporal flicker frequencies of 2, 4, and 8 Hz were obtained. The participants also performed a useful field of view (UFOV) test. The slope coefficient of BOLD activity regarding the temporal frequency of the visual stimulus averaged within V1 regions of interest was positive and significantly different from zero. Group analysis in the V1 showed significant clusters with positive slope and no significant clusters with a negative slope. The correlation coefficient between the slope coefficient and UFOV performance was not significant. The results indicated that V1 BOLD response to a flickering visual stimulus increases as the stimulus temporal frequency increases from 2 to 8 Hz in older adults.

Association of Dietary Variety and Appetite with Sleep Quality in Urban-Dwelling Older Japanese Adults

OBJECTIVES

Although it has been shown that specific foods and nutrients are associated with sleep quality, few studies have examined the association of dietary variety and appetite with sleep quality in older adults.

DESIGN AND SETTING

A cross-sectional study was conducted that examined the association of dietary variety and appetite with sleep quality in Japanese adults aged ≥70 years who resided in the metropolitan area of Tokyo, Japan.

PARTICIPANTS

Data were collected in two steps: a mailed interview survey and an on-site survey. Those who responded to the surveys and met the inclusion criteria were included.

MEASUREMENTS

Dietary variety, appetite, and sleep quality were assessed using a Dietary Variety Score (DVS), Council on Nutrition Appetite Questionnaire (CNAQ) score, and sleep efficiency, respectively. The sleep efficiency is the ratio of sleep duration to total time in bed (retiring time-awakening time). We defined the individuals with a sleep efficiency less than 75% as having poor sleep quality.

RESULTS

Mean DVS and CNAQ score were 3.8 and 29.6 points, respectively. The rate of individuals with poor sleep quality was 11.7%. In the fully adjusted model, the odds ratios (OR) for low sleep efficiency in the middle and highest group categories of the DVS were 0.83 (95% confidence interval [CI], 0.54-1.29) and 0.50 (95% CI, 0.28-0.90), respectively, in reference to the lowest group category (p for trend = 0.023). The OR for low sleep efficiency in the middle and highest group categories of the CNAQ score were 0.73 (95% CI, 0.47-1.14) and 0.54 (95% CI, 0.30-0.96), respectively, in reference to the lowest group category (p for trend = 0.031).

CONCLUSIONS

The higher DVS and CNAQ scores were significantly associated with higher sleep efficiency. Thus, dietary variety and good appetite might help maintain good sleep quality in urban-dwelling older Japanese adults.

Association of Day-to-Day Variations in Physical Activity with Postprandial Appetite Regulation in Lean Young Males

Previous studies have shown that habitual physical activity improves postprandial appetite regulation. We evaluated the direct association between physical activity level (PAL) and postprandial appetite regulation, and the effect of day-to-day variations in PAL on improving postprandial appetite regulation in lean young males. Fourteen young male adults wore a triaxial accelerometer for at least 6 consecutive days to evaluate their PAL. Two random liquid preload tests were performed on separate days to evaluate the competence of postprandial appetite regulation. In the preload test, participants ate sandwiches ad libitum 75 min after drinking one of two liquids containing different energy densities. When a participant had an adequate regulation of their postprandial appetite, the difference in energy intake from sandwiches was expected to be close to the energy gap between both liquids. Average daily PAL (r = −0.558, p < 0.05), but not the SD of PAL, which is indicative of the day-to-day variations in PAL (r = −0.437, p > 0.1), correlated with the difference in energy intake from the sandwiches. In addition, higher average PAL was closer to the energy gap between the two liquids. These results suggest that average daily PAL, rather than day-to-day variations in PAL, predicts inter-individual variation in postprandial appetite regulation, at least for lean young males.