A Cross-sectional Study of the Relationship Between Habitual Tea Consumption and Arterial Stiffness.

BACKGROUND AND AIMS: To explore the relationship between habitual tea consumption and arterial stiffness. METHODS: This is a cross-sectional, epidemiological survey of 6589 male and female residents aged 40-75 in Wuyishan, Fujian Province, China. Tea consumption and other lifestyle characteristics were obtained by structured questionnaires. Pulse wave velocity (PWV) and ankle-brachial pressure index (ABI) were measured using an automated analyzer. RESULTS: Among the 5006 analyzed subjects, 1564 adults (31.2%) consumed tea once or more per week for at least one year. The levels of brachial-ankle pulse wave velocity (ba-PWV) were lowest among subjects who consumed tea habitually for more than 10 years compared with the other 3 subgroups (nonhabitual, 1 to 5 years, and 6 to 10 years habitual tea drinkers), and the levels of ba-PWV were lower with subjects who consumed 10-20 and >20 g/d tea habitually compared to nonhabitual tea drinkers. As the duration and the daily amount of habitual tea consumption increased the average ba-PWV decreased. Multiple logistic regression models revealed that habitual tea consumption was a positive predictor for ba-PWV (odds ratio [OR] = 0.63, 95% confidence interval [CI], 0.57-0.70). CONCLUSIONS: Habitual tea consumption may have a protective effect against arterial stiffness, especially for subjects who have habitually consumed tea for more than 6 years and >10 g daily.

Is alanine aminotransferase associated with osteopenia in middle-aged and elderly Chinese?

OBJECTIVE: To investigate the association between alanine aminotransferase (ALT) levels and risk of osteopenia in middle-aged and elderly Chinese with ALT within the normal range. METHODS: This was a cross-sectional study. A total of 4,890 men and women (pre- and postmenopausal) aged 40 years or older were randomly recruited from Fujian, China. Each participant was required to complete a questionnaire and then undergo anthropometric, biochemical, and bone mineral density measurements. RESULTS: The odds ratio of osteopenia decreased significantly with increasing ALT level at baseline. The three groups (men, pre- and postmenopausal women) were divided by ALT quartiles. In multiple logistic regression models using the first quartile as the reference, after adjusting for corresponding confounding factors, the odds ratios of osteopenia across the other ALT quartiles were 0.576 (95% confidence interval [CI], 0.390 to 0.851), 0.654 (95% CI, 0.460 to 0.930), and 0.629 (95% CI, 0.427 to 0.926) for premenopausal women, and 0.949 (95% CI, 0.699 to 1.289), 0.733 (95% CI, 0.540 to 0.995), and 0.692 (95% CI, 0.508 to 0.943) for postmenopausal women (not significant for quartile 2). However, no significantly different results were found in men. Multiple linear regression models showed that serum ALT concentrations were positively associated with the homeostasis model assessment of insulin resistance. CONCLUSION: Our study of middle-aged and elderly Chinese men and women demonstrates that the prevalence of osteopenia is inversely associated with ALT level when ALT is within the normal range.

Associations of green tea and rock tea consumption with risk of impaired fasting glucose and impaired glucose tolerance in Chinese men and women.

OBJECTIVE: To explore the associations of green tea and rock tea consumption with risk of impaired fasting glucose (IFG) and impaired glucose tolerance (IGT). METHODS: A multistage, stratified, cluster, random-sampling method was used to select a representative sample from Fujian Province in China. In total, 4808 subjects without cardiovascular disease, hypertension, cancer, or pancreatic, liver, kidney, or gastrointestinal diseases were enrolled in the study. A standard questionnaire was used to gather data on tea (green, rock, and black) consumption and other relevant factors. The assessment of impaired glucose regulation (IGR) was using 75-g oral glucose tolerance test (OGTT), the diagnostic criteria of normal glucose tolerance was according to American Diabetes Association. RESULTS: Green tea consumption was associated with a lower risk of IFG, while rock tea consumption was associated with a lower risk of IGT. The adjusted odds ratios for IFG for green tea consumption of <1, 1-15, 16-30, and >30 cups per week were 1.0 (reference), 0.42 (95% confidence intervals (CI) 0.27-0.65), 0.23 (95% CI, 0.12-0.46), and 0.41 (95% CI, 0.17-0.93), respectively. The adjusted odds ratios for IGT for rock tea consumption of <1, 1-15, 16-30, and >30 cups per week were 1.0 (reference), 0.69 (95% CI, 0.48-0.98), 0.59 (95% CI, 0.39-0.90), and 0.64 (95% CI, 0.43-0.97), respectively. A U-shaped association was observed, subjects who consumed 16-30 cups of green or rock tea per week having the lowest odds ratios for IFG or IGT. CONCLUSIONS: Consumption of green or rock tea may protect against the development of type 2 diabetes mellitus in Chinese men and women, particularly in those who drink 16-30 cups per week.

Associations between age at menarche and menopause with cardiovascular disease, diabetes, and osteoporosis in Chinese women.

CONTEXT: Ages at menarche and menopause are associated with cardiovascular disease (CVD), diabetes, and osteoporosis in Caucasian women, but associations remain unexplored in Chinese women. OBJECTIVE: The purpose of this study was to assess associations between age at menarche and menopause with CVD, diabetes, and osteoporosis in Chinese women. DESIGN AND SETTING: A cross-sectional, population-based study was conducted in Fujian, China, from June 2011 to January 2012. PARTICIPANTS: Among 6242 women aged 21 to 92 years, 3304 postmenopausal women were enrolled, excluding premenopausal women (n = 2527), those with unreported ages at menarche and menopause (n = 138), those with unrecorded physical measurements (n = 203), and those with menarche age <8 years or >20 years (n = 70). MAIN OUTCOME MEASURES: An oral glucose tolerance test, a 12-lead resting electrocardiogram, and calcaneus quantitative ultrasound were performed. RESULTS: No significant associations were found between menarche age, diabetes, and osteoporosis (both P > .05); later menarche (>18 years) was significantly associated with lower CVD risk (odds ratio = 0.71, 95% confidence interval, 0.57-0.89; P = .002). Menopause age was not associated with diabetes; higher menopause age was associated with decreasing CVD risk (P for trend = .020) and earlier menopause (≤46 years) with significantly higher osteoporosis risk (odds ratio = 1.59, 95% confidence interval, 1.07-2.36; P = .023). CONCLUSIONS: In China, ages at menarche and menopause are not associated with diabetes. Later menarche and menopause are associated with decreasing CVD risk and earlier menopause with higher osteoporosis risk. Menarche and menopause history may help identify women with increased risk of developing CVD and osteoporosis.

Metabotropic glutamate receptor 5 modulates nociceptive plasticity via extracellular signal-regulated kinase-Kv4.2 signaling in spinal cord dorsal horn neurons.

Metabotropic glutamate receptors (mGluRs) play important roles in the modulation of nociception. The group I mGluRs (mGlu1 and mGlu5) modulate nociceptive plasticity via activation of extracellular signal-regulated kinase (ERK) signaling. We reported recently that the K+ channel Kv4.2 subunit underlies A-type K+ currents in the spinal cord dorsal horn and is modulated by the ERK signaling pathway. Kv4.2-mediated A-type currents are important determinants of dorsal horn neuronal excitability and central sensitization that underlies hypersensitivity after tissue injury. In the present study, we demonstrate that ERK-mediated phosphorylation of Kv4.2 is downstream of mGlu5 activation in spinal cord dorsal horn neurons. Activation of group I mGluRs inhibited Kv4.2-mediated A-type K+ currents and increased neuronal excitability in dorsal horn neurons. These effects were mediated by activation of mGlu5, but not mGlu1, and were dependent on ERK activation. Analysis of Kv4.2 phosphorylation site mutants clearly identified S616 as the residue responsible for mGlu5-ERK-dependent modulation of A-type currents and excitability. Furthermore, nociceptive behavior induced by activation of spinal group I mGluRs was impaired in Kv4.2 knock-out mice, demonstrating that, in vivo, modulation of Kv4.2 is downstream of mGlu5 activation. Altogether, our results indicate that activation of mGlu5 leads to ERK-mediated phosphorylation and modulation of Kv4.2-containing potassium channels in dorsal horn neurons. This modulation may contribute to nociceptive plasticity and central sensitization associated with chronic inflammatory pain conditions.