Chia-n Li

Effect of aging on gender differences in neural control of heart rate

To clarify the influence of gender on sympathetic and parasympathetic control of heart rate in middle-aged subjects and on the subsequent aging process, heart rate variability (HRV) was studied in normal populations of women ( n = 598) and men ( n = 472) ranging in age from 40 to 79 yr. These groups were divided into eight age strata at 5-yr intervals and were clinically diagnosed as having no hypertension, hypotension, diabetic neuropathy, or cardiac arrhythmia. Frequency-domain analysis of short-term, stationary R-R intervals was performed, which reveals very-low-frequency power (VLF; 0.003-0.04 Hz), low-frequency power (LF; 0.04-0.15 Hz), high-frequency power (HF; 0.15-0.40 Hz), the ratio of LF to HF (LF/HF), and LF and HF power in normalized units (LF% and HF%, respectively). The distribution of variance, VLF, LF, HF, and LF/HF exhibited acute skewness, which was adjusted by natural logarithmic transformation. Women had higher HF in the age strata from 40 to 49 yr, whereas men had higher LF% and LF/HF between 40 and 59 yr. No disparity in HRV measurements was found between the sexes in age strata ≥60 yr. Although absolute measurements of HRV (variance, VLF, LF, and HF) decreased linearly with age, no significant change in relative measurements (LF/HF, LF%, and HF%), especially in men, was detected until age 60 yr. We conclude that middle-aged women and men have a more dominant parasympathetic and sympathetic regulation of heart rate, respectively. The gender-related difference in parasympathetic regulation diminishes after age 50 yr, whereas a significant time delay for the disappearance of sympathetic dominance occurs in men.To clarify the influence of gender on sympathetic and parasympathetic control of heart rate in middle-aged subjects and on the subsequent aging process, heart rate variability (HRV) was studied in normal populations of women (n = 598) and men (n = 472) ranging in age from 40 to 79 yr. These groups were divided into eight age strata at 5-yr intervals and were clinically diagnosed as having no hypertension, hypotension, diabetic neuropathy, or cardiac arrhythmia. Frequency-domain analysis of short-term, stationary R-R intervals was performed, which reveals very-low-frequency power (VLF; 0.003-0.04 Hz), low-frequency power (LF; 0.04-0.15 Hz), high-frequency power (HF; 0.15-0.40 Hz), the ratio of LF to HF (LF/HF), and LF and HF power in normalized units (LF% and HF%, respectively). The distribution of variance, VLF, LF, HF, and LF/HF exhibited acute skewness, which was adjusted by natural logarithmic transformation. Women had higher HF in the age strata from 40 to 49 yr, whereas men had higher LF% and LF/HF between 40 and 59 yr. No disparity in HRV measurements was found between the sexes in age strata >/=60 yr. Although absolute measurements of HRV (variance, VLF, LF, and HF) decreased linearly with age, no significant change in relative measurements (LF/HF, LF%, and HF%), especially in men, was detected until age 60 yr. We conclude that middle-aged women and men have a more dominant parasympathetic and sympathetic regulation of heart rate, respectively. The gender-related difference in parasympathetic regulation diminishes after age 50 yr, whereas a significant time delay for the disappearance of sympathetic dominance occurs in men.

Progression to type 2 diabetes among high-risk groups in Kin-Chen, Kinmen. Exploring the natural history of type 2 diabetes.

OBJECTIVE To examine the natural history of 654 high-risk subjects (340 men and 314 women) with fasting hyperglycemia (first fasting plasma glucose [FPG] level 5.6–7.8 mmol/1) who also exhibited 2-h postload glucose concentrations <11.1 mmol/1 and an FPG level <7.8 mmol/1 in a 75-g oral glucose tolerance test (OGTT). We were particularly interested in comparing the likelihood of developing type 2 diabetes for those with persistent fasting hyperglycemia (PFH), impaired glucose tolerance (IGT), and normal glucose tolerance (NGT). PFH is a relatively new definition, and those with PFH used to be defined as NGT according to WHO criteria. RESEARCH DESIGN AND METHODS Subjects were located in a 1992–1994 community-based population survey and followed up and reexamined during 1995–1996. An OGTT was used to determine who had progressed to type 2 diabetes. Risk factors predictive of subsequent progression to type 2 diabetes were determined by comparing baseline variables from the 1992–1994 survey with data of those who had or had not progressed to type 2 diabetes in 1995–1996. RESULTS Of 654 high-risk subjects screened in the baseline survey 481 (73.5%, 255 men and 226 women) were followed up. Of these, 8.1% had progressed to diabetes (4.1% progression/year, 95% Cl 2.3–5.9). Of 131 baseline IGT subjects, 17.6% progressed to diabetes (8.8% progression/year, 6.3–11.3), but only 7.4% of 95 PFH subjects (3.7% progression/year, 2.0–5.4) and 3.5% of 255 NGT subjects (1.8% progression/year, 0.1–3.0) progressed to diabetes. CONCLUSIONS The rates of progression to type 2 diabetes were lowest from the NGT subgroup, highest from the IGT group, with the PFH group in the middle, suggesting that PFH might be a transitional condition that precedes IGT and diabetes. Other significant predictors of subsequent diabetes were baseline BMI, baseline hyperuricemia, baseline FPG, and 2-h plasma glucose concentration.

Relative role of insulin resistance and β-cell dysfunction in the progression to type 2 diabetes—The Kinmen Study

This study compared the relative role of insulin resistance and beta-cell dysfunction (both assessed using the HOMA method) with glucose intolerance conditions in the progression to type 2 diabetes among a high risk group of subjects with fasting plasma glucose (FPG) 5.6-7.0 mmol/l in Kinmen, Taiwan. Data were collected during a continuing prospective study (1998-99) of a group of Taiwanese subjects at high-risk of developing type 2 diabetes who had fasting hyperglycemia (5.6-7.0 mmol/l) and exhibited 2-h postload glucose concentrations <11.1 mmol/l from 1992-94 to 1995-96. Among 644 non-diabetic subjects at baseline, 79.8% (514/644) had at least one follow-up examination. There were 107 new cases of diabetes diagnosed by 1999 WHO criteria in 2918.7 person-years of follow-up. The incidence rate was 3.67%/year (107/2918.7). After adjustment for other possible associative variables, including gender, age, BMI, waist circumference, insulin resistance, and beta-cell dysfunction, Coxs hazard model showed that those individuals with isolated IFG (impaired fasting glucose) and those individuals with isolated IGT (2-h glucose impairment) exhibited similar risk of developing diabetes. Those individuals with isolated IFG and isolated IGT showed a comparable impairment of basal or hepatic insulin sensitivity, but those individuals with isolated IFG had a greater beta-cell dysfunction by the HOMA method.

Epidemiology of type 2 diabetes in Taiwan

In the face of the growing worldwide prevalence of type 2 diabetes, effective methods of preventing further increases in prevalence are needed. In this paper, we review the community-based epidemiologic studies of diabetes in Taiwan published during the last decade, and look at the effectiveness of a two-stage screening protocol for identifying subjects at risk for progression to type 2 diabetes. The results of these studies indicate that the age-adjusted prevalence rate of undiagnosed diabetes in Taiwan is stable, at around 4.0%, while the annual incidence rate is about 1.8%. The results of several studies strongly suggest that a two-step screening strategy, in which only subjects with a fasting plasma glucose level of 5.6-7.8 mmol/l receive the oral glucose tolerance test, may be an effective means of identifying diabetics and persons at high risk for progression to type 2 diabetes and, ultimately, slowing the increase in the prevalence of this disease.

Comparison of the prevalence in two diabetes surveys in Pu-Li, Taiwan, 1987–1988 and 1991–1992

The objective of this study was to investigate the prevalence of non-insulin-dependent diabetes mellitus (NIDDM) in Pu-Li, Taiwan from 1991-1992, and to compare the results with a similar study conducted in 1987-1988. We also wished to compare different approaches in asking about patient history and to determine how this effects data authenticity. Both were community-based cross-sectional studies with stratified cluster sampling of residents age > or = 30. Blood samples were taken for screening and 75 g oral glucose tolerance tests were performed for diagnosis. The total number of eligible subjects in the second study was 2719 (1424 men, 1295 women). Complete data and samples were collected for 1118 (536 men, 582 women). The response rate was 41.1% (37.6% for men, 44.9% for women). The crude prevalence was 10.3% (5.6% known, 4.7% new). Using standard world population (Segi), the age-adjusted prevalence rate was 8.3% (4.0% known, 4.3% new). The 1991-1992 study had a response rate (crude 41.1%, adjusted 51.3%) which was slightly lower than the 1987-1988 study (crude 44.8%, adjusted 55.9%). The age-adjusted prevalence rates for new NIDDM were similar (4.4 vs. 4.3%) while the age-adjusted prevalence of known NIDDM in the second survey (4.0%) was lower than the first survey (6.9%), which apparently was overestimated due to the simplicity of questions regarding history. In conclusion, prevalence of new DM in this area appears to be stable, and when doing a survey regarding previous DM, it is better to include treatment history rather than depending on self-reporting of NIDDM alone.

Comparison of metabolic risk profiles between subjects with fasting and 2-hour plasma glucose impairment: The Kinmen Study

A two-step screening strategy was used to compare the metabolic risk profiles between subjects from Kinmen, Taiwan, who had fasting and 2-hr plasma glucose impairment and were considered at high risk of diabetes due to a fasting plasma glucose (FPG) between 5.6 and 7.8 mmol/l at the baseline screening. 1855 subjects without a previous diagnosis of diabetes who had an FPG of 5.6-7.8 mmol/l at the first step of screening were invited to undergo an Oral Glucose Tolerance Test (OGTT) for the second step of screening, and 1456 of these subjects (774 males and 682 females) completed the OGTT. Subjects who completed the OGTT were classified into normal, isolated impaired fasting glucose (isolated IFG), isolated impaired glucose tolerance (isolated IGT), both IFG and IGT, or undiagnosed diabetes groups. Sex-specific, age-adjusted mean values of metabolic risk profiles for various categories of glucose intolerance were calculated. The results for IFG and IGT agreed in only 20.8% of subjects. The clinical features of subjects with IGT (2-hr glucose impairment) were associated with cardiovascular risk profiles, while those subjects with isolated IFG (fasting glucose impairment only) were not. If the definition of IFG alone had been used for glucose intolerance screening, about 66.6% of subjects with IGT (i.e., isolated IGT with 2-hr glucose impairment and a normal fasting state) who had cardiovascular risk profiles would have been undetected.

Joint predictability of health related quality of life and leisure time physical activity on mortality risk in people with diabetes

BackgroundReduced health related quality of life (HRQOL) has been associated with increased mortality in individuals with diabetes. In contrast, increased leisure time physical activity (LTPA) has been associated with reduced mortality. The aim of this study was to investigate the combined relationship of HRQOL and LTPA on mortality and whether high levels of LTPA are associated with reduced risk of mortality in adults with diabetes and inferior HRQOL.MethodsWe analyzed data from a national sample of adults (18 years or older) with self-reported physician-diagnosed diabetes, who participated in the 2001 National Health Interview Survey in Taiwan (N = 797). A total of 701 participants had complete Short Form 36 (SF-36) and LTPA data and were followed from 2002 to 2008. Participants were divided into 3 groups based on their LTPA: (1) a regularly active group who reported 150 or more min/week of moderate-intensity activity; (2) an intermediately active group who reported engaging in LTPA but did not meet the criterion for the “regular” category; and (3) an inactive group who reported no LTPA. The physical component summary (PCS) and mental component summary (MCS) scores were dichotomised at the median (high vs. low) (PCS = 45.11; MCS = 47.91). Cox proportional-hazards models were used to investigate associations between baseline characteristics and mortality.ResultsAfter 4,570 person-years of follow-up, 121 deaths were recorded and the crude mortality rate was 26.5 per 1,000 person-years. Both PCS scores and LTPA were significant predictors of mortality, whereas no significant relationship was observed between MCS and mortality. After adjustment for other factors, participants with low PCS who reported no LTPA had a hazard ratio (HR) for mortality of 4.49 (95% CI = [2.15-9.36]). However, participants with low PCS who were active (including intermediate and regular LTPA) had a HR for mortality of 1.36 (95% CI = [0.64-2.92]).ConclusionsOur results show a significantly increased mortality risk of diabetes associated with reduced HRQOL in individuals who report no LTPA. Engaging in LTPA may be associated with improved survival in participants with diabetes with poor self-rated physical health status.

Diabetes, functional ability, and self-rated health independently predict hospital admission within one year among older adults: A population based cohort study

The aims of the present study were to determine the relationships among diabetes, functional ability and self-rated health, and whether they predict subsequent hospital admission in a representative sample of older adults. We conducted a prospective study on persons aged 65 and above (N=2064) who participated in the National Health Interview Survey in Taiwan, 2001. A total of 1609 participants consented to data linkage and were successfully linked to 2002 National Health Insurance claims data. Functional ability was defined as the ability to perform six activities of daily living (ADL). After adjustment for potential confounders, older adults with diabetes were significantly more likely to have ADL limitation and worse self-rated health and had an increased risk of hospitalization. Diabetes, ADL limitation and worse self-rated health all independently predicted hospital admission within one year. Older adults with diabetes, ADL limitation and worse self-rated health are important target populations for interventions aimed at preventing hospitalization.

Community-based epidemiological study of glucose tolerance in Kin-Chen, Kinmen: support for a new intermediate classification.

In this population-based survey, we investigated the prevalence of varying degrees of glucose tolerance among residents of Kin-Chen, Kinmen, as well as the association of glucose tolerance status with potential risk factors for type 2 diabetes and cardiovascular disease (CVD). We focused particularly on subjects with normal 2-h postload glucose level (<7.8 mmol/l) but persistent fasting hyperglycemia (PFH) (5.6-7.8 mmol/l), to examine whether PFH represents an intermediate state between normal glucose tolerance (NGT) and impaired glucose tolerance (IGT). The target population comprised 6346 residents aged 30 years and older. A total of 4354 subjects could be classified into categories of NGT, PFH, IGT, new diabetes, and known diabetes according to medical history, fasting plasma glucose levels, and the results of a 75-g oral glucose tolerance test (OGTT). The potential cardiovascular risk factors assessed included age, obesity (general and central), systolic blood pressure, and fasting levels of insulin, C-peptide, triglyceride, cholesterol, and high-density lipoprotein cholesterol (HDL-C). The age-standardized prevalences of PFH, IGT, new diabetes, and known diabetes were 2.9%, 3.5%, 4.0%, and 3.0%, respectively. Among nondiabetic subjects, the cardiovascular risk factor profiles worsened with decreasing glucose tolerance, with most values differing significantly among the NGT, PFH, and IGT groups. Subjects with PFH, who would be classified as having NGT according to conventional WHO criteria, had physical and biochemical features between those of the NGT and IGT groups. These findings support our previous observation that PFH may be a transition state between NGT and IGT in the progression toward type 2 diabetes.

Changes in decisional conflict and decisional regret in patients with localised prostate cancer

AIMS AND OBJECTIVES To identify the changes and associated factors in decisional conflict and regret in patients with localised prostate cancer up to six months postprimary treatment. BACKGROUND Various treatments of differing qualities can be used for patients with localised prostate cancer; these treatments may cause conflicts in treatment decision-making and post-treatment regret. DESIGN A quantitative longitudinal study. METHODS A total of 48 patients were recruited from a 3700-bed medical centre in northern Taiwan and assessed at pretreatment and one and six months post-treatment. Demographic characteristics, clinical information and results from the psychosocial adjustment to illness scale, decisional conflict scale and decision regret scale were collected. Data were analysed based on the generalised estimating equations models. RESULTS The overall decisional conflict substantially improved over time. However, the feeling of being less informed was high and did not improve considerably during the study period. Education level, decision preferences and psychosocial adjustment were associated with decisional conflict and influenced decision-making. The feeling of ineffective decision-making and decisional regret was low, post-treatment. Psychosocial adjustment was associated with effective decision-making and decisional regret. CONCLUSION In patients with localised prostate cancer, decisional conflict reduced considerably up to six months post-treatment. Moreover, the patients were satisfied with their treatment decision-making and believed that they had made the correct choice up to six months post-treatment. However, patients may have experienced feelings of being less informed pre- and post-treatment, particularly those with lower education levels, a preference for passive roles, or inferior psychosocial adjustment. Consequently, health professionals must provide adequate medical information and psychosocial intervention to help patients in the decision-making process. RELEVANCE TO CLINICAL PRACTICE Nurses and healthcare providers must provide localised prostate cancer patients with adequate information and psychosocial intervention to reduce decisional conflict.