Mio Nakazato

Thyroid function is associated with carotid intima-media thickness in euthyroid subjects.

To investigate the relationship between thyroid function and carotid intima-media thickness (CIMT) in a relatively large general population with euthyroid status we initially enrolled 1772 Japanese adults (421 men and 1351 women) who participated in a medical screening program for the general population over 40 years old. To evaluate only euthyroid subjects without vascular diseases and/or its major risk factors, 1129 were excluded and 643 participants (175 men and 468 women) were included for further analysis. Simple and multivariate linear regression analyses were performed to evaluate free thyroxine (fT4) and thyroid-stimulating hormone (TSH) levels and other existing parameters, including carotid intima-media thickness. By multivariate linear regression analysis adjusted for age and sex, free thyroxine was significantly correlated with triglycerides (beta=0.07, p=0.015), carotid intima-media thickness (beta=-0.091, p=0.049), and thyroid-stimulating hormone (beta=-0.091, p=0.003). Thyroid-stimulating hormone was significantly correlated with high-density lipoprotein cholesterol (HDL-C) (beta=-0.001, p=0.015), HbA(1c) (beta=0.038, p=0.045), carotid intima-media thickness (beta=0.27, p=0.001), and free thyroxine (beta=-0.15, p=0.003). When adjusted for confounding factors, free thyroxine was significantly correlated only with carotid intima-media thickness (beta=-0.13, p=0.043) and thyroid-stimulating hormone was significantly correlated with HDL-C (beta=-0.001, p<0.001), HbA(1c) (beta=0.04, p=0.021), and carotid intima-media thickness (beta=0.29, p=0.001). We have demonstrated that carotid intima-media thickness is independently associated with thyroid function within the normal reference range, which suggests an increased cardiovascular risk in subjects with low normal thyroid function.

Relationship Between Periodontal Status and HbA1c in Nondiabetics

OBJECTIVES Many studies have reported an association between diabetes and periodontitis. We analyzed the periodontal status and glycosylated hemoglobin (HbA1c) level in nondiabetic subjects to investigate the relationship between periodontitis and glucose control in nondiabetics. METHODS Periodontal status, HbA1c, serum cholesterol, triglyceride, body mass index (BMI), and demographic variables were assessed in 141 Japanese adults. The difference in the HbA1c level was evaluated among subjects according to periodontal status. RESULTS After adjusting for age, gender, BMI, and smoking, alcohol, and exercise habits as covariates, the mean HbA1c was significantly elevated with periodontal deterioration (P = 0.023). CONCLUSIONS There was a significant relationship between periodontal status and HbA1c levels in nondiabetics.

A validated HPLC-fluorescence method with a semi-micro column for routine determination of homocysteine, cysteine and cysteamine, and the relation between the thiol derivatives in normal human plasma.

A semi-micro column HPLC-fluorescence method for routine determination of thiol derivatives such as homocysteine (Hcy), cysteine (Cys) and cysteamine (CA) is described. The thiol derivatives labeled with ammonium-7-fluorobenzo-2-oxa-1,3-diazole-4-sulfonate (SBD-F) were isocratically separated within 12 min on a semi-micro ODS column (Daisopak-SP-120-5-ODS-BP) with a mixture of 25 mm acetate buffer (pH 2.00) and CH(3)CN as a mobile phase. The purity and similarity of SBD-thiols by a multi-wavelength fluorescence detector were more than 92.3 and 96.7%. The detection limits of Hcy, Cys and CA at a signal-to-noise ratio of 3 were 0.16, 0.47 and 0.03 microm, respectively. Furthermore validation parameters such as accuracy, precision and robustness of the proposed method showed satisfactory results. Almost 850 plasma sample injections (range 572-1076, n = 3) for a column could be performed without differences in retention time and peak heights of labels. As an application of the proposed method, the determination of thiol derivatives in normal human plasma (n = 103) was demonstrated. The correlation coefficients between Hcy vs Cys and Hcy vs CA were 0.38 and -0.35, respectively.

Evaluation of clinical markers of atherosclerosis in young and elderly Japanese adults.

Abstract Background: In order to be able to take preventative measures early in life against the development of atherosclerosis, it is important to evaluate profiles of subclinical atherosclerosis, especially among young adults. Methods: We screened plasma homocysteine levels, highly sensitive C-reactive protein levels and carotid intima-media thickness in young and elderly adults. Results: Among both young and elderly adults, plasma homocysteine and highly sensitive C-reactive protein were significantly lower in females than in males. Highly sensitive C-reactive protein was significantly lower in young adults than in elderly adults, and homocysteine was lower (but not significantly) in young adults than in elderly adults. Among young adults, mean carotid intima-media thickness was lower (but not significantly) in females than in males. Among elderly adults, mean carotid intima-media thickness was significantly lower in females than in males. Among both males and females, mean carotid intima-media thickness was significantly higher in elderly adults than in young adults. Conclusions: These results demonstrate basic profiles of atherosclerosis markers in young and elderly Japanese adults. Further study is needed to evaluate measures developed for application in early adulthood to prevent atherosclerosis. Clin Chem Lab Med 2006;44:824–9.

White blood cell count and cardiovascular biomarkers of atherosclerosis.

Objective: To investigate the association with white blood cells (WBC) and atherosclerotic parameters including cardio-ankle vascular index (CAVI) and carotid intima–media thickness (CIMT) in the general population. Methods: We investigated the relationship between WBC count and metabolic syndrome components, CAVI and CIMT in 3738 Japanese study participants. Results: WBC count weakly correlated with CAVI in men (β = 0.61, p = 0.043), but not in women (β = 0.35, p = 0.17). On the other hand, WBC did not correlate with CIMT in either men or women (p = 0.41 and p = 0.71, respectively). Conclusion: WBC count was associated with lipids, blood pressure and body mass index, although the correlations with CAVI and CIMT were weak or absent.

Leptin to high-molecular-weight adiponectin ratio is independently correlated with carotid intima-media thickness in men, but not in women.

Background: The leptin:adiponectin ratio (L:A ratio) is an independent predictor of carotid intima-media thickness (CIMT). Objective: To evaluate whether the leptin:high-molecular-weight adiponectin ratio (L:HA ratio) is associated with CIMT in the general population. Methods: We investigated the relationship between the L:HA ratio and CIMT in 233 Japanese study participants (106 men and 127 women). Results: After adjustment for confounding factors, CIMT was significantly correlated with the log L:HA ratio (β = 0.11, p = 0.014) in men, whereas no correlation was observed in women (β = 0.01, p = 0.50). Conclusion: The L:HA ratio is closely correlated with CIMT in men, but not in women.

Association between hemoglobin levels and arterial stiffness for general Japanese population in relation to body mass index status: The Nagasaki Islands study

To investigate associations between hemoglobin levels and arterial stiffness accounting for body mass index (BMI) in a large‐scale cross‐sectional study.

Association of the GCKR rs780094 Polymorphism with Metabolic Traits Including Carotid Intima-Media Thickness in Japanese Community-dwelling Men, but Not in Women

Abstract Background: The glucokinase regulator gene (GCKR) rs780094 has been shown to be strongly associated with some metabolic traits and atherosclerotic parameters, while the association between GCKR rs780094 and carotid intima-media thickness (CIMT) has not been fully investigated in the general population. The associations between the GCKR rs780094 genotype and metabolic traits including CIMT were examined in a Japanese community-dwelling population. Methods: A total of 2491 Japanese adults (907 men and 1584 women) who participated in a medical screening program for the general population from 29 to 94 years of age during 2008 to 2010 were enrolled. GCKR rs780094 was genotyped by the TaqMan polymerase chain reaction method, and associations with metabolic markers including CIMT were evaluated. Results: GCKR rs780094 AA genotype was significantly associated with higher TG (p<0.001 vs. GG), lower HDL-C (p=0.021 vs. GG), and lower HbA1c(p=0.023 vs. GG). The AA genotype showed significantly thinner CIMT (p=0.001 vs. GX). These associations were seen only in men. Conclusions: GCKR rs780094 was associated with TG, HDL-C, and HbA1c levels, as well as with CIMT in Japanese community-dwelling men, but not women.

Multimers and adiponectin gene 276G>T polymorphism in the Japanese population residing in rural areas.

BACKGROUND Although it has been shown that high-molecular weight adiponectin is an active form, few studies have attempted to clarify the relationship between high molecular weight adiponectin and markers linked with cardiovascular diseases in the general population. METHODS We screened 236 Japanese study participants recruited from the general population, residing in one large and four small islands. In addition to serum lipids and lipoproteins, serum total adiponectin and each multimer were measured. The genotype single-nucleotide polymorphism 276G>T was detected in real-time PCR with LightCycler hybridization probes, using fluorescent-labeled nucleotides. RESULTS Multiple linear regression analysis showed that high-molecular weight adiponectin, as well as total adiponectin, were significantly correlated with body weight, body mass index, high-density lipoprotein cholesterol and triglycerides. Total adiponectin and high-molecular weight adiponectin concentrations were not significantly different between GG and TX (GT and TT) genotypes of 276G>T polymorphism in the adiponectin gene. Interestingly, no differences were observed for participants from the large island between GG and TX genotypes with regard to both total adiponectin and high-molecular weight adiponectin, whereas significant differences were observed for those from the small islands. CONCLUSIONS Our results show that total adiponectin and high-molecular weight adiponectin are associated with similar factors in the general population. Furthermore, different effects of 276G>T for participants from small and large islands suggest that regional background due to geographic barriers may control the effects of 276G>T on adiponectin concentrations.

Height and drinking status in relation to risk of anemia in rural adult healthy Japanese men: the Nagasaki Islands study

Abstract Background: Several studies have reported that height is inversely associated with risk of cardiovascular disease but positively associated with cancer risk. On the other hand, evidence has been accumulating that anemia reflects poor health and increased vulnerability to poor outcomes in older persons. Moreover, alcohol consumption has also been reported to be associated with mortality. However, no studies have reported on a possible association between height and risk of anemia in relation to drinking status. Methods: We conducted a cross-sectional study of 1287 men aged 40–89 years undergoing general health check-ups. Results: Independent from classic cardiovascular risk factors, we found a significant inverse association between height and anemia for non-drinkers and a J-shaped association for drinkers. The multivariable odds ratio (ORs) of an increment of 1 SD (standard deviation) in height (6.68 cm) for anemia for non-drinkers was 0.59 (0.45–0.77). For drinkers, with the second quartile of height (Q2) as the reference group, the multivariable OR of anemia was 2.68(0.90–7.96) (p = 0.075) for the lowest height quartile (Q1), 2.73(0.92–8.08) for the third quartile (Q3) and 4.82(1.65–14.10) for the highest quartile (Q4) (p = 0.004). Conclusion: Height was found to be associated with anemia for rural Japanese men and drinking status is likely to affect those associations.