We examined the child-rearing environmental factors that affect the occurrence of sudden infant death syndrome (SIDS) using a nationwide survey. Infants who died due to SIDS between January 1996 and June 1997 in Japan were identified from death certificates. Controls of the same gender, birthplace, and birth months as the corresponding SIDS were chosen from birth certificates. Interviews of both cases and controls were undergone in January and February, 1998 by public health nurses. The following child-rearing factors exhibited a significant relationship with the occurrence of SIDS: Concerning the sleeping position, the prone position was associated with increased risk compared with the supine position, with an odds ratio of 3.02 (95% c.i. 2.07~4.65). Regarding the feeding method, artificial feeding alone demonstrated a higher risk than breast feeding alone, with an odds ratio of 4.92 (95% c.i. 2.78~9.63). With regard to smoking, infants with both parents who smoked exhibited a higher risk than infants where neither parent smoked, with an odds ratio of 3.50 (95% c.i. 1.74~8.32).
Sudden infant death syndrome ; occurrence ; Lower case sea ; Risk ; Affect

In an attempt to study the effect of a moderate work load on the concentration of serum erythropoietin and hemoglobin in young women, 8 female university students with a high hemoglobin content (group H), 7 female university students with a low hemoglobin content (group L) and 7 female university students with a tendency to be anemic (group A) were subjected to moderate work for 7 successive days in summer.
Each subject pedalled at a constant work load of 1.25kp at a cycling rate of 50rpm for 60min every day. Blood samples were drawn from the cubital vein under basal conditions on the day before training, the fourth day of training and the day after the training period. The results obtained were as follows; Group H showed a significantly higher erythropoietin concentration before training than groups L and A. The concentration of erythropoietin in group H decreased slightly during the training period, whereas those in groups L and A increased, although the differences were not statistically significant.
The concentration of serum iron in group H was significantly higher than that in group L before training. The former decreased significantly during the training period, whereas the latter was maintained at a lower level. The differences in blood constituents found among the three groups before training lessened after one week's moderate exercise.
The increase in Hb concentration in the subjects in groups L and A after training might have been induced by the augmented secretion of erythropoietin due to training for 7 successive days.

The present study aimed to examine the effects of community-based intervention on cognitive function and hand finger dexterity in older adults at different levels of time to go out. Forty men and women (age, 73 ± 1 years) participated in supervised group activity and seated exercise for 60 min per session, once each week during an 8-week intervention. The participants wore an activity monitor for 1 week to determine baseline values and for the 8 weeks of intervention. Mini-mental state examination (MMSE) and pegboard test, which is related to cognitive function, were assessed before and after the intervention. Based on the total time to go out at baseline, the participants were assigned to Control group (> 60 min/day, n = 18) or Short group (≦ 60 min /day, n = 22), and then analyzed. After the 8 weeks of intervention, the Control and Short groups improved physical fitness parameters such as handgrip strength. Although MMSE in the both groups did not reach statistically significant level, these values tended to increase slightly from the baseline. Interestingly, two-way repeated-measures analysis of variance indicated significant interaction of pegboard test, and the score significantly increased only in the Short group. Total physical activity and moderate-vigorous physical activity in the both groups did not change significantly between the baseline and intervention periods. Therefore, these results suggest that the trainability of pegboard test, which is an index of hand finger dexterity and is related to cognitive function, would differ depending on the time to go out at baseline in older adults.

Although the physical activity reference value for older adults (10 METs*hour/week) has been promoted by Japan Ministry of Health, Welfare, and Labour since 2013, little is known about how many steps/day cut-off values that optimally identify meeting the reference value according to the differences of age, sex, medical history, and joint pain. The purpose of this study were 1) to determine the steps/day that optimally identify meeting the reference value, and 2) to identify the differences by the effects of age, sex, medical history, and joint pain on cut-off values. This study included 583 community-dwelling older Japanese adults (aged 73.2 ± 5.4 years; 153 men, 430 women). A uniaxial accelerometer survey was conducted to estimate the total physical activity volume and steps/day. Receiver operating characteristic (ROC) analyses were used to detect steps/day cut-off values for meeting the reference value among all participants and stratified by age, sex, medical history, and joint pain. The optimal cut-off value (AUC (area under the ROC curve), sensitivity, and specificity) for the reference value was 4376 steps/day (0.99, 95.2%, and 97.2%) in all participants. Differences among the cut-off values according to age, sex, medical history, and joint pain ranged from 39 to 169 steps/day. These results suggest that step counts has satisfactory validity to represent the reference value in older adults, and the effects of age, sex, medical history, and joint pain on cut-off values were considerably small. Therefore, this step-count level may be a useful indicator for modifying the daily-life activities of older adults.

The purpose of this study was to examine the effects of 9 weeks of resistance training, with and without static acceleration training (AT), on participants' lower-limb muscle strength, power, and physical function. Healthy participants (19 men and 28 women), aged 65-75 years, were assigned to a static AT group (AT, n = 31) or a non-AT control group (C, n = 16). The AT group and the C group trained three times/week for 9 weeks. The AT group performed unloaded static AT and low-intensity aerobic activity. The C group performed dynamic weight-bearing resistance training without whole-body vibration and the same aerobic activity as the AT group. We collected and analyzed data from 45 participants (AT = 30, C = 15) who completed pre- and post-tests. There was no significant Group × Time interaction on any measurements of lower-limb muscle strength, power, or physical function. Significant time effects were observed in the following tests:isokinetic knee extensor and flexor peak torque, 5-time sit-to-stand, usual gait speed, timed up and go, standing time from a long sitting position, and sit and reach. All of these 7 variables showed positive changes. These results suggest that static AT is a suitable training method having approximately the same efficiency as conventional, weight-bearing, dynamic resistance training for improving lower-limb muscle strength and power, mobility, and flexibility in community-dwelling Japanese older adults.

This study aimed to examine the association between body mass index (BMI) and muscle strength, and mobility limitation (ML). A cross-sectional analysis was conducted on data from 570 community-dwelling older Japanese women aged 65-91 years [mean age, 73.9 ± 5.8 (SD) years]. Muscle strength was assessed by hand-grip strength (HGS). ML was assessed using self-reported difficulty level in walking 400 m and ascending 10 steps without resting. BMI and muscle strength were divided into tertiles (high: BMI ≧ 25.1 kg/m², HGS ≧ 22.5 kg; middle: BMI 22.4-25.0 kg/m², HGS 18.8-22.4 kg; low: BMI ≦ 22.3 kg/m², HGS ≦ 18.7 kg) respectively, and logistic regression analysis was used to determine the association between BMI and muscle strength with ML. 256 participants (44.9%) were identified as having ML. Adjusted odds ratios of BMI for ML were 1.64 (95% confidence interval (CI): 1.00-2.68) in the middle group and 1.89 (95% CI: 1.15-3.12) in the high group when compared to the low group. Adjusted odds ratios of muscle strength for ML were 1.25 (95% CI: 0.77-2.04) in the middle group and 1.85 (95% CI: 1.11-3.09) in the low group when compared to the high group. Compared to the low BMI plus high muscle strength group, adjusted odds ratio for ML was significantly higher in the high BMI plus low muscle strength group (2.65, 95% CI: 1.02-6.87) and the high BMI plus middle muscle strength group (3.09, 95% CI: 1.25-7.61). Our findings indicate that the combination of overweight plus muscle weakness is more predictive for having ML than overweight or muscle weakness alone.

The purpose of this study was to retrospectively examine the association of habitual exercise with “single fall (= 1)”, “multiple falls (≥ 2)”, and “injurious falls (≥ 1)” among community-dwelling older adults. A total of 1,683 community-dwelling older adults, aged 60-97 years (72.6 +/- 6.6 yr, 512 men and 1,171 women) were included in this study. Habitual exercises continued one year or longer (6.4 +/- 9.5 yr) were classified into twelve types. Exercise components (time, quantity, period of continuity, and number of exercises) were divided with median or tertiles. To assess the association between habitual exercises and fall status, multivariable logistic regression analyses with stepwise selection method, were applied. The multivariable logistic regression analyses showed that dance (odds ratio (OR): 0.30, 95% confidence interval (CI): 0.09-0.96) was negatively associated with “single fall”. Bicycling (OR: 3.72, 95% CI: 1.32-10.77) was positively associated with “multiple falls”, and the period of continuity (OR: 0.74, 95% CI: 0.60-0.91) was negatively associated with “multiple falls”. None of the exercise components were selected with regard to “injurious falls”. Results indicate that dance may be an effective type of exercise for fall prevention among community-dwelling older adults. However, caution about falling is warranted toward bicycling as an exercise. Moreover, a longer period of continuity (≥ 4 years) appears to be a positive factor of habitual exercise for fall prevention.

The purpose of this study was to examine the association between the hierarchy of higher-level functional capacity (instrumental self-competence, intellectual activity, social role) and the quantity of physical activity in older women (n = 175, 72.1 ± 5.8 years). Physical activity was estimated with a uniaxial accelerometer that calculated light-intensity physical activity (LPA), and moderate-to vigorous-intensity physical activity (MVPA). Higher-level functional capacity was assessed with the Tokyo Metropolitan Institute of Gerontology (TMIG) index of competence. According to the three subscales (instrumental self-competence, intellectual activity, and social role) of the TMIG index, participants who reported a score of 1 or more below the respective full marks were categorized as a group with reduced status. Logistic regression analysis was conducted to examine association between the hierarchy of higher-level functional capacity and the quantity of physical activity divided by intensity of activity, adjusted by covariance. Only low MVPA showed a significantly lower odds ratio than high MVPA in reduced status of instrumental self-competence. Since instrumental self-competence was significantly related with only the quantity of MVPA, it may be more important to focus on “quantity” of physical activity to prevent reductions in higher-level functional capacity in advanced stages of declining functional capacity.

Bicuspid aortic valve (BAV) is one of the more common congenital anomalies. It is well known that the ascending aorta and aortic root sometimes dilate in patients with BAV, even when the valve function is normal. We examined the morphological type and histological features of the dilated ascending aorta in patients with BAV. Of 276 patients who underwent aortic valve replacement (including coronary artery bypass grafting) from 2004 onwards, 60 (21.5%) with BAV were included in this study. The type of BAV was defined according to the Sievers classification. Type 1 BAV was the most common, and enlargement of the ascending aorta (≥45 mm) was the most common in the L/R type of BAV (48%). The morphology of the dilated ascending aortic wall was evaluated using three-dimensional CT angiography. The majority of dilations were asymmetric, but dilation was symmetric in the patient with dilation of the aortic root. Histological examination graded cystic medial necrosis of the ascending aortic walls using the aortic wall score. All patients with BAV had degeneration of the aortic wall, even when there was no dilation. The aortic walls of patients with dilated aortic roots showed advanced degeneration compared with the aortic walls of other patients. Therefore, aggressive root replacement may be appropriate, when the root is mildly dilated in patient with BAV.