Akiko Yura

Breastfeeding and the prevalence of symptoms of allergic disorders in Japanese adolescents

Background Environmental factors acting early in life are key determinants of the incidence of allergic disease. Whether breastfeeding is protective against allergic disorders remains controversial.

Ecological association of water hardness with prevalence of childhood atopic dermatitis in a Japanese urban area.

The prevalence of symptoms of atopic eczema among Japanese children aged 6-7 years is the second highest in 56 countries. Reasons for such a high prevalence are unknown. This ecological study examined whether the positive association of water hardness with atopic dermatitis among British primary-school children also exists in Japan. Study subjects were 458,284 of 489,725 children, aged 6-12 years, in 1,016 public elementary schools in Osaka Prefecture with 44 municipalities. The study used data on water hardness and chlorine content of the water supply; prevalence of atopic dermatitis diagnosed by physicians and episodes of wheezing reported by the parents; and potential confounding factors by socioeconomic and health care status per municipality. The prevalence of atopic eczema was significantly higher in the highest water hardness category than that in the lowest (24.4% [n=2,288/9,362] and 22.9% [n=77,408/33,8267], respectively; adjusted odds ratio 1.12, 95% confidence interval 1.06-1.18; P<0.0001 for trend). A significant and slightly J-shaped relationship between chlorine content of the water supply and prevalence of atopic dermatitis was observed after adjustment for confounding factors. There were no apparent associations of water hardness and chlorine content of the water supply with prevalence of wheeze. Water hardness may increase the risk of atopic dermatitis among elementary-school children in Japan, as well as in the United Kingdom.

Cross-sectional study of allergic disorders in relation to familial factors in Japanese adolescents.

Aim: The roles of heredity and the household environment in the development of allergic disorders are not clearly established. This study examined the relationship between selected familial factors and the prevalence of symptoms of wheeze, atopic eczema and rhinoconjunctivitis in Japanese adolescents. Methods: Study subjects were 5539 students aged 12–15 y in Suita City. A questionnaire ascertained gender, grade, number of older siblings, maternal age at childbirth, smoking in the household, domestic pets and parental history of allergy, as well as signs and symptoms of allergy in the previous 12 mo. The latter were based on diagnostic criteria from the International Study of Asthma and Allergies in Childhood. Results: Male gender was independently associated with an increased prevalence of wheeze and a decreased prevalence of atopic eczema. The prevalence of rhinoconjunctivitis, but not wheeze or atopic dermatitis, significantly increased with advancing grade. A significant inverse dose‐response relationship between the number of older siblings and the prevalence of rhinoconjunctivitis, but not wheeze or atopic dermatitis, was observed. Maternal age at childbirth, smoking in the household and domestic pets were not apparently related to any of the allergic disorders. A positive maternal allergic history was more evidently associated with an increased prevalence of wheeze and rhinoconjunctivitis, but not atopic eczema, than a positive paternal allergic history.

Alcohol intake and bone status in elderly Japanese men: Baseline data from the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) Study

There are no data concerning a relationship between alcohol and bone status from a large-scale community-based study of elderly Japanese men. The baseline survey for the Fujiwara-kyo Osteoporosis Risk in Men Study was performed in 2174 male participants during the period from 2007 to 2008 in Nara Prefecture, Japan. Among them 1665 fitted the following inclusion criteria: (a) age ≥65years, (b) no diseases or drug therapy that could affect bone mineral density (BMD). We analyzed 1421 men with complete information about alcohol intake. We found that alcohol intake and BMD were positively correlated after adjustment for age, body mass index, natto intake, milk intake, smoking, physical activity, education, marital status, and hypertension. Adjusted total hip BMD of men with alcohol intake >39g/day was 0.90g/cm(2) and that of abstainers was 0.85g/cm(2). With regard to bone turnover markers, alcohol intake was inversely associated with serum levels of osteocalcin and tartrate-resistant acid phosphatase isoenzyme 5b. A two-piece linear regression model revealed a positive relationship between alcohol intake and crude mean BMD for the total hip in those with alcohol intake of less than 55g/day. In contrast, alcohol intake and BMD in those with an alcohol intake of 55g/day or more was inversely correlated. The present large-scale study of elderly Japanese men revealed that although an alcohol intake of <55g/day was positively correlated to BMD, alcohol intake of ≥55g/day was inversely correlated to BMD.

Design and baseline characteristics of a prospective cohort study for determinants of osteoporotic fracture in community-dwelling elderly Japanese men: the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) Study

AbstractBackgroundOsteoporosis and osteoporotic fracture in men are significant public health problems in an aging society. However, information on male osteoporosis remains impressively lacking, especially for Asians. We designed the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) study as an ancillary study of a cohort study, the Fujiwara-kyo study, to determine risk factors for osteoporotic fractures in Japanese men.Methods/DesignDesign: A community-based single-centre prospective cohort study with at least a 5-year follow-up Subjects: All the male participants of the Fujiwara-kyo study who were living in the four cities studied, aged 65 years and older, and able to walk without aid from others. Primary outcome: Incidence of osteoporotic fractures including vertebral and clinical non-vertebral fractures. Additional outcomes: Change in bone mineral density (BMD), change in hip geometry, onset of receiving benefits from Long-term Care Insurance (LCI), health-related quality of life, and mortality. Baseline measurements: BMD at the lumbar spine (LS) and hip (TH), hip geometry, vertebral deformity assessment, bone turnover markers, physical and cognitive performance, various medical and lifestyle factors, and geriatric psychosocial measures confirmed by interviews based on self-administrated questionnaires. Outcome surveillance: Annual mail surveys and a follow-up survey at the fifth year comprising similar items to the baseline study will be used to determine the outcomes. Receipt of benefits from LCI and mortality will be obtained from the city governments. Current status: The baseline study was conducted for 2174 eligible men, and 2012 completed the study and were eligible for follow-up. Prevalence rates of osteoporosis (BMD 2.5 SD or more below the young adult mean (YAM)) and low BMD (BMD 1 SD or more below YAM) in at least one of LS and TH were calculated to be 4.4% and 41.8%, respectively. The proportion of men with low BMD only at TH showed a significant increasing trend with aging (p < 0.0001) while that only at LS showed a decreasing trend (p = 0.0386). The prevalence rate of osteoporosis was underestimated when diagnosed using only BMD at LS. Other baseline measurements were successfully obtained.DiscussionFORMEN baseline study was performed as designed and the FORMEN cohort study was successfully launched.

Trends of allergic symptoms in school children: large-scale long-term consecutive cross-sectional studies in Osaka Prefecture, Japan.

To cite this article: Yura A, Kouda K, Iki M, Shimizu T. Trends of allergic symptoms in school children: large‐scale long‐term consecutive cross‐sectional studies in Osaka Prefecture, Japan. Pediatr Allergy Immunol 2011; 22: 631–637.

Hyperglycemia is associated with increased bone mineral density and decreased trabecular bone score in elderly Japanese men: The Fujiwara-kyo osteoporosis risk in men (FORMEN) study

PURPOSE Patients with type 2 diabetes mellitus (T2DM) have an increased fracture risk despite having higher areal bone mineral density (aBMD). This study aimed to clarify the association between glycemic and insulin resistance status and bone microarchitecture, and whether pentosidine and bone turnover markers play any roles in the association. METHODS A total of 2012 community-dwelling men aged ≥65years completed baseline measurements of spine aBMD, fasting plasma glucose (FPG) and serum insulin, hemoglobin A1c (HbA1c), osteocalcin, type I procollagen N-terminal propeptide, type I collagen C-terminal crosslinking telopeptide, tartrate-resistant acid phosphatase isoenzyme 5b, pentosidine, height and weight and an interview regarding past disease history. Homeostasis model assessment-insulin resistance (HOMA-IR) was also calculated. T2DM was defined as physician-diagnosed middle age or elderly-onset diabetes mellitus, or according to biochemical test results. To evaluate bone microarchitecture, trabecular bone score (TBS) was calculated at the same vertebrae as those used for aBMD measurement. RESULTS After excluding participants who had a disease history and/or were taking medications affecting bone metabolism, 1683 men (age, 72.9±5.2years) were analyzed. Men with T2DM had significantly higher aBMD compared to those without T2DM. There was no significant difference in TBS. However, FPG, HbA1c and HOMA-IR levels were significantly inversely correlated with TBS after adjusting for age, BMI and aBMD. Multivariate linear regression analyses revealed that glycemic indices (FPG and HbA1c) were significantly associated with increased aBMD and decreased TBS, and that HOMA-IR was associated only with TBS. These associations did not change after further adjusting for bone turnover makers and pentosidine levels. CONCLUSIONS Hyperglycemia and elevated insulin-resistance were associated with low TBS independently of bone turnover and pentosidine levels.

Renal function and bone mineral density in community-dwelling elderly Japanese men: The Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) Study

End-stage renal failure deteriorates bone mass and increases fracture risk. However, there are conflicting reports in the literature regarding the effects of mild to moderate renal dysfunction on bone mineral density (BMD). We investigated the association between renal function and BMD at the spine and hip and bone metabolism markers in community-dwelling elderly Japanese men. From 2174 male volunteers aged ≥65 years, we examined 1477 men after excluding those with diseases or medications known to affect bone metabolism. Renal function was assessed by serum cystatin C and estimated glomerular filtration rate (eGFR) calculated using the Modification of Diet in Renal Disease Study equation. Bone metabolism was evaluated using levels of serum amino-terminal propeptide of type I procollagen (PINP) and tartrate-resistant acid phosphatase isoenzyme 5b (TRACP-5b), which represent bone metabolic status independent of renal function. eGFR was inversely associated with BMD after adjusting for potential confounders (P < 0.01). Cystatin C showed a weaker but significant association with BMD. eGFR was modestly positively associated with PINP levels (P = 0.04), although cystatin C concentrations were neither associated with PINP nor TRACP-5b levels. Since BMD integrates bone metabolism from the past to present, inverse associations between renal function and BMD may be attributed to past factors, such as obesity. Our findings suggest that low renal function does not affect bone metabolism in a population of community-dwelling elderly Japanese men. Longitudinal studies will be necessary to clarify whether low renal function affects bone loss.

Ratio of Endogenous Secretory Receptor for Advanced Glycation End Products to Pentosidine Predicts Fractures in Men.

Context Although the endogenous secretory receptor for advanced glycation end products (esRAGE) has been associated with reduced activity of pentosidine (PEN), the association between PEN, esRAGE, and fracture is poorly understood. Objectives To evaluate the ability of serum PEN and esRAGE levels to predict fragility fractures. Methods A cohort of 1285 Japanese men aged ≥65 years old participated in a 2007 to 2008 Fujiwara-kyo Osteoporosis Risk in Men study baseline survey, as part of the Fujiwara-kyo prospective cohort study. Those participants provided information regarding any fractures they experienced during 5 years. The baseline bone mineral density (BMD) was measured. Hazard ratios (HRs) per one standard deviation increase of log-transformed serum levels of PEN, esRAGE, and esRAGE-to-PEN ratio were estimated at baseline. Results Twenty-five participating men suffered incident clinical fragility fractures. The crude HRs (95% confidence interval) for PEN, esRAGE, and esRAGE-to-PEN ratio were 1.56 (1.05 to 2.31), 0.79 (0.54 to 1.15), and 0.65 (0.44 to 0.95), respectively. HRs for PEN adjusted for age, esRAGE, and T score of BMD at femoral neck (FN) and lumbar spine (LS) were 1.48 (1.00 to 2.18) and 1.51 (1.03 to 2.21), respectively. The marginal significance adjusted for BMD at FN and the statistical significance adjusted for BMD at LS were attenuated after additional adjustment for glycated hemoglobin A1c level (P = 0.111 and 0.072, respectively). The HRs for esRAGE-to-PEN ratio adjusted for age, glycated hemoglobin A1c, and T-score of BMD at FN and LS were 0.67 (0.45 to 0.98) and 0.64 (0.43 to 0.95). Conclusions Higher esRAGE-to-PEN ratios were associated with decreased risk of fragility fractures independent of BMD among elderly Japanese men.

Response to “Effects of Vitamin K intake on gamma-carboxylated proteins, bone fractures, and vascular calcifications”

We would like to thank Maria Fusaro and colleagues for their suggestion that habitual intake of natto may have a beneficial effect on vascular health, as well as bone health, via vitamin K-dependent matrix Gla protein (MGP), a potent inhibitor of arterial calcification [1]. This is interesting because we know that MGP may be carboxylated only in the presence of vitamin K2, which is enriched in natto [2]. A systematic review of the relationship between vitamin K and coronary heart disease (CHD) showed no association between vitamin K1 intake and the incidence of CHD, whereas increased intake of vitamin K2 is associated with fewer CHD events [3]. Thus, vitamin K2 may be a more important factor in the prevention of CHD than vitamin K1. In addition, a usual portion size of natto (50 g) contains approximately 380 μg of vitamin K2 (menaquinone-7) [4], while the mean vitamin K2 intake in the cohort studies cited by Rees et al. [3] was only 30 μg/day, with a maximum intake of 128 μg/day [5, 6]. A Japanese population consuming natto would have a higher dietary vitamin K2 intake than other populations. The Japanese Population-based Osteoporosis Cohort Study showed that postmenopausal women with no or low natto intake exhibited significantly greater hip bone loss than those with habitual natto intake [7] and that low spine bone density or prevalent vertebral fractures in postmenopausal women are independently associated with increased intima–media thickness (IMT) at the carotid bifurcation [8]. These findings suggest that low natto intake may be associated with increased IMT, a surrogate marker for CHD. In contrast, another report in the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) Study showed that serum levels of undercarboxylated osteocalcin, a biomarker for vitamin K intake, are inversely associated with glycemic index and insulin resistance [9], suggesting that natto intake may increase the risk of diabetes mellitus, which is a potent risk factor for CHD [10]. Therefore, it is not clear whether vitamin K intake has beneficial effects on vascular health, in addition to bone health. As Fusaro and colleagues pointed out, we should investigate the effects of vitamin K on vascular calcification with a careful consideration of the interaction between vitamin K and intake of calcium and vitamin D. The risk of diabetes mellitus should also be investigated. We will conduct a follow-up survey on the FORMEN Study population for fracture assessment and IMT measurement and prospectively examine the association between natto This is a reply to the letter that can be found at doi 10.1007/s00198011-1689-8.