Genetic evidence for involvement of ß2-adrenergic receptor in brown adipose tissue thermogenesis in humans.

BACKGROUND: Sympathetic activation of brown adipose tissue (BAT) thermogenesis can ameliorate obesity and related metabolic abnormalities. However, crucial subtypes of the ß-adrenergic receptor (AR), as well as effects of its genetic variants on functions of BAT, remains unclear in humans. We conducted association analyses of genes encoding ß-ARs and BAT activity in human adults. METHODS: Single nucleotide polymorphisms (SNPs) in ß1-, ß2-, and ß3-AR genes (ADRB1, ADRB2, and ADRB3) were tested for the association with BAT activity under mild cold exposure (19 °C, 2 h) in 399 healthy Japanese adults. BAT activity was measured using fluorodeoxyglucose-positron emission tomography and computed tomography (FDG-PET/CT). To validate the results, we assessed the effects of SNPs in the two independent populations comprising 277 healthy East Asian adults using near-infrared time-resolved spectroscopy (NIRTRS) or infrared thermography (IRT). Effects of SNPs on physiological responses to intensive cold exposure were tested in 42 healthy Japanese adult males using an artificial climate chamber. RESULTS: We found a significant association between a functional SNP (rs1042718) in ADRB2 and BAT activity assessed with FDG-PET/CT (p < 0.001). This SNP also showed an association with cold-induced thermogenesis in the population subset. Furthermore, the association was replicated in the two other independent populations; BAT activity was evaluated by NIRTRS or IRT (p < 0.05). This SNP did not show associations with oxygen consumption and cold-induced thermogenesis under intensive cold exposure, suggesting the irrelevance of shivering thermogenesis. The SNPs of ADRB1 and ADRB3 were not associated with these BAT-related traits. CONCLUSIONS: The present study supports the importance of ß2-AR in the sympathetic regulation of BAT thermogenesis in humans. The present collection of DNA samples is the largest to which information on the donor's BAT activity has been assigned and can serve as a reference for further in-depth understanding of human BAT function.

Dietary behaviours and related lifestyles according to the presence or absence of skipping breakfast in Japanese adults: the JPHC-NEXT study.

OBJECTIVE: To assess dietary behaviours and related lifestyles according to the presence or absence of skipping breakfast. DESIGN: We analysed the cross-sectional data from a baseline survey of a large-scale population-based cohort study in Japan conducted in 2011-2016. Participants provided information on dietary behaviours and lifestyles through a self-administered questionnaire. Skipping breakfast was defined as not eating breakfast at least once a week and was classified according to the frequency of skipping breakfast as 1-2, 3-4 or ≥5 times/week. SETTING: Sixteen municipalities in seven prefectural areas across Japan under the Japan Public Health Centre-based prospective study for the Next Generation. PARTICIPANTS: 112 785 residents (51 952 males and 60 833 females) aged 40-74 years. RESULTS: After adjustment for age, socio-demographic status, drinking status and smoking status, individuals who skipped breakfast at least once a week, compared with those who ate breakfast every day, were more likely to have adverse dietary behaviours such as frequent eating out (multivariable OR = 2·08, 95 % CI (1·96, 2·21) in males and 2·15, 95 % CI (1·99, 2·33) in females), frequent eating instant foods (1·89, 95 % CI (1·77, 2·01) in males and 1·72, 95 % CI (1·56, 1·89) in females). They had late bedtime (1·85, 95 % CI (1·75, 1·95) in males and 1·98, 95 % CI (1·86, 2·11) in females) and living alone (2·37, 95 % CI (2·17, 2·58) in males and 2·02, 95 % CI (1·83, 2·21) in females), using the logistic regression model. CONCLUSIONS: Both adult males and females who skipped breakfast were likely to eat out, to have a dietary habit of eating instant foods and have lifestyles such as late bedtime and living alone than those who ate breakfast.

Vasoreactivity of the optic nerve head, nailfold, and facial skin in response to cold provocation in normal-tension glaucoma patients.

BACKGROUND: The dysfunction of optic nerve head (ONH) hemodynamics has been suggested to be involved in the pathogenesis of normal-tension glaucoma (NTG). The aim of this study was to compare vasoreactivity in the ONH, nailfold, and facial skin in response to cold-water provocation in NTG patients and healthy controls. METHODS: We performed cold-water provocation in 14 eyes of 14 NTG patients and 15 eyes of 15 age-matched control subjects. Laser speckle flowgraphy-derived tissue-area mean blur rate (MT), skin blood flowmetry-derived pulse wave amplitude (PA), nailfold capillaroscopy-derived nailfold capillary diameter, and other clinical parameters were recorded at baseline and 4 and 6 min after the cold stimulus. We compared changes (as percentages) in these variables in the NTG and control subjects with a linear mixed-effects model and evaluated correlations between these changes with Spearman's rank correlation coefficient. RESULTS: The interaction term between the NTG group (reference, control group) and the 4-min protocol step (reference, baseline) significantly affected the changes in MT, nailfold capillary diameter and PA (ß = -9.51%, P = 0.017, ß = -20.32%, P = 0.002; ß = + 18.06%, P = 0.017, respectively). The change in MT was positively correlated with the change in nailfold capillary diameter, and negatively correlated with the change in PA (r = 0.39, P = 0.036; r = -0.40, P = 0.031, respectively). CONCLUSION: NTG patients showed abnormal vasoconstriction in the ONH and nailfold and vasodilation in the facial skin in response to cold-water provocation.

Association Between Birth Weight and Risk of Pregnancy-Induced Hypertension and Gestational Diabetes in Japanese Women: JPHC-NEXT Study.

BACKGROUND: Although prevalence of low birth weight has increased in the last 3 decades in Japan, no studies in Japanese women have investigated whether birth weight is associated with the risk of pregnancy complications, such as pregnancy-induced hypertension (PIH) and gestational diabetes mellitus (GDM). METHODS: We used data from the Japan Public Health Center-based Prospective Study for the Next Generation (JPHC-NEXT), a population-based cohort study in Japan that launched in 2011. In the main analysis, we included 46,365 women who had been pregnant at least once, for whom information on birth weight and events during their pregnancy was obtained using a self-administered questionnaire. Women were divided into five categories according to their birth weight, and the relationship between birth weight and risk of PIH and GDM was examined using multilevel logistic regression analyses with place of residence as a random effect. RESULTS: Compared to women born with birth weight of 3,000-3,999 grams, the risk of PIH was significantly higher among women born <1,500 grams (adjusted odd ratio [aOR] 1.60; 95% confidence interval [CI], 1.17-2.21), 1,500-2,499 grams (aOR 1.16; 95% CI, 1.03-1.30), and 2,500-2,999 grams (aOR 1.13; 95% CI, 1.04-1.22). The risk of GDM was significantly higher among women born 1,500-2,499 grams (aOR 1.20; 95% CI, 1.02-1.42), albeit non-significant association among women in other birthweight categories. CONCLUSIONS: We observed an increased risk of PIH among women born with lower birth weight albeit non-significant increased risk of GDM among Japanese women.

Association between self-reported walking speed and calcaneal stiffness index in postmenopausal Japanese women.

BACKGROUND: Osteoporosis and related fractures, a worldwide public health issue of growing concern, is characterized by compromised bone strength and an increased risk of fracture. Here we show an association between self-reported walking speed and bone mass among community-dwelling postmenopausal Japanese women aged 50 years and older. DESIGN; CROSS-SECTIONAL STUDY: Setting and Participants; The survey population included 1008 postmenopausal women 50-92 years of age residing in rural communities. METHODS: Self-reported walking speed was ascertained by asking the participants: "Is your walking speed faster than others of the same age and sex?" to which participants responded "yes (faster)" or "no (moderate/slower)." Calcaneal stiffness index was measured. RESULTS: Women with a faster self-reported walking speed were younger and had a lower BMI, higher stiffness index, and higher grip strength than women with a slower walking speed. Multiple linear regression analysis adjusted for age, BMI, grip strength, comorbidity, current smoking, and alcohol drinking status showed a significant association between faster self-reported walking speed and higher calcaneal stiffness index (p <  0.001). CONCLUSIONS: Our findings suggest that questionnaires of walking speed may be useful for predicting bone mass and that a fast self-reported walking may benefit bone health in postmenopausal women.

Relationship between bone turnover markers and the heel stiffness index measured by quantitative ultrasound in post-menopausal Japanese women.

Background: Osteoporosis in women is a serious health problem. The relationships between biochemical markers of bone turnover and bone mineral density (BMD) in women have been reported, but no study has examined relationships between tartrate-resistant acid phosphatase-5b (TRACP-5b) or bone-specific alkaline phosphatase (BAP) and bone mass measured by quantitative ultrasound (QUS) in Japanese post-menopausal women. Aim: To investigate the serum TRACP-5b and BAP levels and to determine their associations with the heel stiffness index measured by QUS in post-menopausal women. Subjects and methods: The subjects were 510 post-menopausal women who were invited to participate in periodic health examinations in 2011-2013 (the Unzen Study). The heel stiffness index (bone mass) was measured by QUS. Serum samples were collected and TRACP-5b and BAP levels were measured. Results: Multiple regression analysis showed that a higher log (TRACP-5b) was correlated with a lower stiffness index (p = 0.014) and log (BAP) was not correlated with stiffness index after adjusting for covariates (p = 0.136). Conclusion: Higher rates of bone resorption are associated with a lower stiffness index in Japanese post-menopausal women. These results may indicate that high bone resorption affects bone mass more than bone formation, resulting in a low bone mass.

[Association between fear of falling and activities of daily living among community-dwelling Japanese older adults].

Objectives　This study aimed to explore the association of difficulties in activities of daily living (ADL) (activities related to bending, spine extension, standing endurance, and walking) with fear of falling among community-dwelling older adults.Methods　We recruited 642 older adults (men, n=267; women, n=375) aged 65 years and over. The mean age was 72.2±5.1 years. Fear of falling, falls in the previous year, pain (low back pain or knee pain), comorbidity, and cataracts were assessed using a self-administered questionnaire. ADL difficulties were assessed individually, such as activities related to bending (getting in or out the car, picking up a lightweight object, putting on socks or stockings, and lifting a 5 kg object from the floor), spine extension (reaching an object above your head), standing endurance (standing on your feet for 2 h), and walking (walking 100 m on a level surface, climbing 10 steps without stopping, and walking down 10 steps). The independent association between fear of falling and each ADL difficulties was assessed using logistic regression analysis.Results　Participants with fear of falling, compared with those without fear of falling, had an older age (74.8 and 71.6 in men, 73.3 and 71.0 in women, respectively; P<0.01), more falls in the previous year (21% and 9% in men, 28% and 11% in women, respectively; P<0.05), pain (80% and 61% in men, 82% and 64% in women, respectively; P<0.01), and comorbidity (23% and 15% in women, respectively; P<0.05). Multivariate logistic regression analysis identified each ADL difficulties except walking 100 m on a level surface as being independently associated with fear of falling after adjusting for age, body mass index, sex, falls in the previous year, pain, and comorbidity.Conclusion　ADL difficulties, such as activities related to bending, spine extension, standing endurance, and walking, except for walking 100 m on a level surface, were associated with fear of falling.

Association of vertebral compression fractures with physical performance measures among community-dwelling Japanese women aged 40 years and older.

BACKGROUND: Numerous reported studies have shown that vertebral compression fractures are associated with impaired function or disability; however, few examined their association with objective measures of physical performance or functioning. METHODS: We examined the association of vertebral compression fractures with physical performance measures in 556 Japanese women aged 40-89 years. Lateral spine radiographs were obtained and radiographic vertebral compression fractures were assessed by quantitative morphometry, defined as vertebral heights more than 3 SD below the normal mean. Measures of physical performance included walking speed, chair stand time and functional reach. Adjusted means of performance-based measures according to the number and severity of vertebral compression fractures were calculated using general linear modeling methods. RESULTS: After adjusting for age, body mass index, back pain, number of painful joints, number of comorbidities and regular physical activities, the walking speed of women with two or more compression fractures (1.17 m/s) was significantly slower than that of women without compression fracture (1.24 m/s) (p = 0.03). Compared with women without compression fracture, chair stand time was longer in women with two or more compression fractures (p = 0.01), and functional reach was shorter (p = 0.01). No significant differences were observed in walking speed, chair stand time, or functional reach between women with one compression fracture and those without compression fracture. CONCLUSIONS: Having multiple vertebral compression fractures affects physical performance in community-dwelling Japanese women. Poor physical functioning may lead to functional dependence, accelerated bone loss, and increased risk for falls, injuries, and fractures. Preventing vertebral compression fracture is considered important for preserving the independence of older adults.

Effect of repeated forearm muscle cooling on the adaptation of skeletal muscle metabolism in humans.

This study aimed to investigate the effect of repeated cooling of forearm muscle on adaptation in skeletal muscle metabolism. It is hypothesized that repeated decreases of muscle temperature would increase the oxygen consumption in hypothermic skeletal muscle. Sixteen healthy males participated in this study. Their right forearm muscles were locally cooled to 25 °C by cooling pads attached to the skin. This local cooling was repeated eight times on separate days for eight participants (experimental group), whereas eight controls received no cold exposure. To evaluate adaptation in skeletal muscle metabolism, a local cooling test was conducted before and after the repeated cooling period. Change in oxy-hemoglobin content in the flexor digitorum at rest and during a 25-s isometric handgrip (10% maximal voluntary construction) was measured using near-infrared spectroscopy at every 2 °C reduction in forearm muscle temperature. The arterial blood flow was occluded for 15 s by upper arm cuff inflation at rest and during the isometric handgrip. The oxygen consumption in the flexor digitorum muscle was evaluated by a slope of the oxy-hemoglobin change during the arterial occlusion. In the experimental group, resting oxygen consumption in skeletal muscle did not show any difference between pre- and post-intervention, whereas muscle oxygen consumption during the isometric handgrip was significantly higher in post-intervention than in pre-test from thermoneutral baseline to 31 °C muscle temperature (P < 0.05). This result indicated that repeated local muscle cooling might facilitate oxidative metabolism in the skeletal muscle. In summary, skeletal muscle metabolism during submaximal isometric handgrip was facilitated after repeated local muscle cooling.

Exercise intervention implemented by trained volunteers improves health-related quality of life among Japanese community-dwelling older females: an intervention study.

[Purpose] This study aimed to evaluate the sustainability and efficacy of exercise intervention, as implemented by professionally trained volunteers, on the health-related quality of life among Japanese community-dwelling older females. [Subjects and Methods] We conducted a non-randomized observational prospective study of a six-month exercise intervention delivered by volunteers or health professionals. Health-related quality of life was scored using the Short Form 36 Health Survey before and after the intervention. Participants were classified into three groups, comprising those with improved health, maintained health, and reduced health. [Results] Among 127 Japanese community-dwelling females aged >65 years, 50 of 62 (80.6%) females involved in the intervention conducted by volunteers, and 55 of 65 (84.6%) females involved in the intervention conducted by health professionals, completed the six-month intervention program. Scoring revealed that interventions by both volunteers and health professionals had a maintaining or improving effect on scores in >70% of participants instead of an expected six-month aging decline. [Conclusion] Exercise intervention by trained volunteers was sustainable and effective for improving the health-related quality of life among Japanese community-dwelling older females. Professionally trained volunteers could benefit communities in helping older persons avoid the need for daily nursing care through promoting health activities.

Prevalence of lumbar spondylosis and its association with low back pain among community-dwelling Japanese women.

BACKGROUND: Lumbar spondylosis is more prevalent among the middle-aged and elderly, but few population-based studies have been conducted, especially in Japan. The purpose of this study was to explore the prevalence of lumbar spondylosis and its associations with low back pain among community-dwelling Japanese women. METHODS: Lateral radiographs of the lumbar spine were obtained from 490 Japanese women ≥ 40 years old, and scored for lumbar spondylosis using the Kellgren-Lawrence (KL) grade at lumbar intervertebral level from L1/2 to L5/S1. Height and weight were measured, and body mass index (BMI) was calculated. Low back pain in subjects was assessed using a self-administered questionnaire. Stiffness index (bone mass) was measured at the calcaneal bone using quantitative ultrasound. RESULTS: Prevalence of radiographic lumbar spondylosis for KL ≥ 2, KL ≥ 3 and low back pain were 76.7%, 38.8% and 20.0%, respectively. Age was positively associated with radiographic lumbar spondylosis (KL = 2, KL ≥ 3) and low back pain. Greater BMI was associated with lumbar spondylosis with KL = 2, but not with KL ≥ 3. Stiffness index was associated with neither radiographic lumbar spondylosis nor low back pain. Multiple logistic regression analysis identified radiographic lumbar spondylosis (KL ≥ 3) at L3/4, L4/5 and L5/S1 was associated with low back pain, independent of age, BMI and stiffness index. CONCLUSION: Severe lumbar spondylosis at the middle or lower level may contribute to low back pain.

Nonthermal sensory input and altered human thermoregulation: effects of visual information depicting hot or cold environments.

A recent study showed that thermoregulatory-like cardiovascular responses can be invoked simply by exposure to visual information, even though the thermal environments are neutral and unchanged. However, it was not clear how such responses affect actual human body temperature regulation. We investigated whether such visually invoked physiological responses can substantively affect human core body temperature in a thermally challenging cold environment. Participants comprised 13 graduate or undergraduate students viewing different video images containing hot, cold, or no scenery, while room temperature was gradually lowered from 28 to 16 °C over 80 min. Rectal temperature, mean skin temperature, core to skin temperature gradient, and oxygen consumption were measured during the experiment. Rectal temperature was significantly lower when hot video images were presented compared to when control video images were presented. Oxygen consumption was comparable among all video images, but core to skin temperature gradient was significantly lower when hot video images were presented. This result suggests that visual information, even in the absence of thermal energy, can affect human thermodynamics and core body temperature.

Illusory self-motion (vection) may be inhibited by hypobaric hypoxia.

INTRODUCTION: Previous reports have shown that higher altitudes can alter human perception. We add further evidence to this claim, describing a new finding in which higher altitudes inhibit the perception of illusory self-motion, i.e., vection. METHOD: We compared vection strength under both normal and high altitude (hypobaric hypoxia) conditions. In the high altitude condition, atmospheric pressure in the climatic chamber was decreased to 13,123 ft (4000 m; 492 ft/150 m x min(-1)) for 28 min and then maintained at the 13,123-ft (4000-m) level for 30 min by a preprogrammed operation. Vection was induced by an optic flow stimulus. RESULTS: Significant differences were observed between the normal and high altitude conditions for all three of the vection strength measurements (latency, duration, and magnitude). Vection was decreased by 14.6%, and Spo2 was decreased by 16.7% in the hypoxia condition. CONCLUSION: Vection was inhibited in the high altitude condition. Applications of this finding include informing aircraft pilots of this effect of self-motion perception inhibition at higher altitudes to promote safer flying.

Association between physical performance and bone mass in community-dwelling postmenopausal Japanese women: The Unzen study.

BACKGROUND: Low bone mass is an independent risk factor for osteoporotic fractures. We examined the association between physical performance and bone mass using quantitative ultrasound in community-dwelling postmenopausal Japanese women. METHODS: We conducted a cross-sectional study on 524 community-dwelling postmenopausal Japanese women who were not being administered osteoporosis medications. Physical performance was assessed on the basis of grip strength, chair stand time, and functional reach. The stiffness index was measured as a quantitative ultrasound parameter for heel bone mass. RESULTS: Physical performance, assessed by grip strength, chair stand time, and functional reach, and the stiffness index significantly decreased with age (both p<0.001). The multiple linear regression analysis showed that grip strength (p = 0.001), chair stand time (p = 0.004), and functional reach (p = 0.048) were significantly associated with the stiffness index after adjusting for age, body mass index, smoking, drinking, and exercise. CONCLUSIONS: Physical performance was significantly associated with heel bone mass in community-dwelling postmenopausal Japanese women.

Cell-cell interaction determines cell fate of mesoderm-derived cell in tongue development through Hh signaling.

Dysfunction of primary cilia leads to genetic disorder, ciliopathies, which shows various malformations in many vital organs such as brain. Multiple tongue deformities including cleft, hamartoma, and ankyloglossia are also seen in ciliopathies, which yield difficulties in fundamental functions such as mastication and vocalization. Here, we found these tongue anomalies in mice with mutation of ciliary protein. Abnormal cranial neural crest-derived cells (CNCC) failed to evoke Hh signal for differentiation of mesoderm-derived cells into myoblasts, which resulted in abnormal differentiation of mesoderm-derived cells into adipocytes. The ectopic adipose subsequently arrested tongue swelling formation. Ankyloglossia was caused by aberrant cell migration due to lack of non-canonical Wnt signaling. In addition to ciliopathies, these tongue anomalies are often observed as non-familial condition in human. We found that these tongue deformities could be reproduced in wild-type mice by simple mechanical manipulations to disturb cellular processes which were disrupted in mutant mice. Our results provide hints for possible future treatment in ciliopathies.

Endocrine, inflammatory and immune responses and individual differences in acute hypobaric hypoxia in lowlanders.

When lowlanders are exposed to environments inducing hypobaric hypoxia (HH) such as high mountains, hemodynamic changes occur to maintain oxygen levels in the body. However, changes to other physiological functions under such conditions have yet to be clarified. This study investigated changes in endocrine, inflammatory and immune parameters and individual differences during acute HH exposure using a climatic chamber (75 min of exposure to conditions mimicking 3500 m) in healthy lowlanders. Aldosterone and cortisol were significantly decreased and interleukin (IL)-6, IL-8 and white blood cell (WBC) counts were significantly increased after HH. Lower peripheral oxygen saturation (SpO2) was associated with higher IL-6 and WBC counts, and higher IL-8 was associated with higher cortisol. These findings suggest that endocrine, inflammatory and immune responses are evoked even with a short 75-min exposure to HH and individuals with lower SpO2 seemed to show more pronounced responses. Our results provide basic data for understanding the physiological responses and interactions of homeostatic systems during acute HH.

Individual variations and sex differences in hemodynamics and percutaneous arterial oxygen saturation (SpO2) in Tibetan highlanders of Tsarang in the Mustang district of Nepal.

BACKGROUND: Many studies have indicated specific low-hemoglobin (Hb) adaptation to high altitude in the Tibetan population, but studies focusing on physiological variations within this population are limited. This study aimed to investigate the relationships between SpO2 and related factors, including individual variations and sex differences, to assess the generality of high-altitude adaptation in the Tibetan population of Tsarang. METHODS: The participants were 31 male and 41 female community-dwelling people aged ≥18 years living in Tsarang, in the Mustang district of Nepal. Height, weight, SpO2, Hb concentration, finger temperature, heart rate, and blood pressure were measured. Lifestyle information was obtained by interview. RESULTS: Men had significantly higher systolic blood pressure (p = 0.002) and Hb (p < 0.001) than women. There was no significant correlation between SpO2 and other parameters in men. In women, SpO2 was negatively correlated with heart rate (p = 0.036), Hb (p = 0.004), and finger temperature (p = 0.037). In multiple regression analysis, a higher SpO2 was marginally correlated with lower age (ß = -0.109, p = 0.086) and higher Hb (ß = 0.547, p = 0.053) in men. In women, higher SpO2 was significantly correlated with lower heart rate (ß = -0.045, p = 0.036) and Hb (ß = -0.341, p = 0.018). Mean hemoglobin (95% confidence interval) was 13.6 g/dl (13.1-14.0 g/dl), which is lower than that found previously in Andeans and almost equal to that in Japanese lowlanders measured using the same device. In some participants of both sexes, hemoglobin was >17.0 g/dl. CONCLUSION: Higher SpO2 was marginally correlated with younger age and higher Hb in men and with lower heart rate and lower Hb in women. Hemoglobin concentration was similar to that found previously in lowlanders, but higher in some individuals. These results indicate individual variation and sex differences in the hemodynamics of high-altitude adaptation in Tibetan highlanders of Tsarang, as well as low-Hb adaptation to high altitude equal to that of other Tibetans.

Association between sarcopenia and respiratory function in elderly orthopedic outpatients.

The relationship between sarcopenia and respiratory function has not been investigated in elderly Japanese orthopedic outpatients. This study aimed to assess the relationship between sarcopenia and respiratory function in elderly orthopedic outpatients in Japan. Elderly outpatients (n = 102; aged ≥65 years) with orthopedic diseases were enrolled in the study. Muscle mass was measured using the bioelectrical impedance analysis. Grip strength and walking speed were measured (2 trials). The respiratory function (e.g., percent vital capacity [VC] and percent forced expiratory volume in 1 second) was also measured. The association between sarcopenia and respiratory function was assessed using logistic regression analysis, adjusting for sex, comorbidities, and smoking status. The mean ages for men and women were 77.7 ± 8.3 and 76.5 ± 6.8 years, respectively, and the overall prevalence of sarcopenia was 25.5% (30.0% and 24.4% in men and women, respectively). The study demonstrated that low respiratory function, which was represented by decreased percent VC, was associated with sarcopenia in outpatients visiting an orthopedic department (odds ratio, 1.73; 95% confidence interval: 1.02-2.97). Sarcopenia was significantly associated with a lower percentage of VC in orthopedic outpatients after adjustment for sex, comorbidity, and smoking. Further studies are needed to determine the causality.

Effects of saliva collection using cotton swabs on melatonin enzyme immunoassay.

BACKGROUND: Although various acceptable and easy-to-use devices have been used for saliva collection, cotton swabs are among the most common ones. Previous studies reported that cotton swabs yield a lower level of melatonin detection. However, this statistical method is not adequate for detecting an agreement between cotton saliva collection and passive saliva collection, and a test for bias is needed. Furthermore, the effects of cotton swabs have not been examined at lower melatonin level, a level at which melatonin is used for assessment of circadian rhythms, namely dim light melatonin onset (DLMO). In the present study, we estimated the effect of cotton swabs on the results of salivary melatonin assay using the Bland-Altman plot at lower level. METHODS: Nine healthy males were recruited and each provided four saliva samples on a single day to yield a total of 36 samples. Saliva samples were directly collected in plastic tubes using plastic straws, and subsequently pipetted onto cotton swabs (cotton saliva collection) and into clear sterile tubes (passive saliva collection). The melatonin levels were analyzed in duplicate using commercially available ELISA kits. RESULTS: The mean melatonin concentration in cotton saliva collection samples was significantly lower than that in passive saliva collection samples at higher melatonin level (>6 pg/mL). The Bland-Altman plot indicated that cotton swabs causes relative and proportional biases in the assay results. For lower melatonin level (<6 pg/mL), although the BA plots didn't show proportional and relative biases, there was no significant correlation between passive and cotton saliva collection samples. CONCLUSION: Our findings indicate an interference effect of cotton swabs on the assay result of salivary melatonin at lower melatonin level. Cotton-based collection devices might, thus, not be suitable for assessment of DLMO.

Association between vitamin D and bone mineral density in Japanese adults: the Unzen study.

We showed an association between serum concentrations of vitamin D and bone health among community-dwelling adults in Japan after adjustment for confounding factors, with 730 participants in a city, with concentrations of 25(OH) vitamin D, and with parameters of quantitative ultrasound. PURPOSE: The primary objective of this study was to examine the correlation between serum 25-hydroxyvitamin D (25(OH)D) concentration and bone indicators as measured by quantitative ultrasound in middle-aged and older Japanese adults living in low-latitude seaside areas during summer and autumn. METHODS: We conducted a cross-sectional study, the Unzen study, on community-dwelling Japanese adults who participated to periodic health examinations between 2011 and 2013 (during the months of May to November). RESULTS: A total of 301 men (mean (SD) age, 67.9 (8.2) years; range, 50-92 years) and 429 women (mean (SD) age, 67.9 (7.7); range, 50-89 years) participated in this study. Serum 25(OH)D levels and quantitative ultrasound parameters (broadband ultrasound (BUA), speed of sound (SOS), and stiffness index of the calcaneus were measured for the participants. We excluded two men and 28 women from the 730 participants because they were on medication for osteoporosis. So, 299 men and 401 women were included in the final data analysis. The prevalence of vitamin D insufficiency (< 30 ng/ml) was very high: 71.9% in men and 95.5% in women. In women, the log(25(OH)D) positively and significantly correlated with SOS (p = 0.011) and stiffness index (p = 0.028) but not with BUA (p = 0.176). In men, the log(25(OH)D) did not correlate with the BUA, SOS, or stiffness index (p = 0.218, 0.420, and 0.262, respectively). CONCLUSIONS: Serum 25(OH)D levels were associated with SOS or stiffness index in women but not in men.