Biomedical subjects

Peifeng Hu

Publications and source records attributed to Peifeng Hu.

12 recordsLinked to original sources

PubMed2025

Prevalence and causes of anemia among older adults in India: findings from wave 2 of the Harmonized Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD).

Anemia among older adults aged ≥ 60 years is a well-described risk factor that increases the risk of falls, cardiovascular diseases, and mortality. In India, objectively measured national estimates of anemia prevalence and the causes of anemia among older adults are lacking. The Harmonized Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD) collected venous blood samples from a nationally representative sample of 3,252 individuals in wave 2 of the study. Out of these, 3,009 samples were used to estimate national prevalence and regional differences in anemia prevalence and its underlying causes. Anemia was defined as hemoglobin < 13 mg/dl in males and < 12 mg/dl in females and further categorized into nutritional and non-nutritional anemia based on several nutritional (ferritin, Vitamin B12, and folate), inflammatory (ferritin, C-reactive protein), and renal (serum creatinine) biomarkers. The overall national anemia prevalence was 49.92%. Anemia prevalence was significantly higher among women (53.9%) than men (45.8%). Among those with anemia, nutritional anemia was found in 63.5% of the respondents, with isolated iron deficiency anemia being the most common cause (51.8%). Among the non-nutritional category, anemia of chronic disease was the most common type (31.4%). About 10% of all anemia cases could not be classified into either category using the available data. Regional differences were seen with the highest prevalence of anemia in Assam, West Bengal, Jharkhand, and Odisha, and the lowest prevalence (< 30%) in Jammu & Kashmir and Haryana. Multivariate adjustment showed that age, sex, and region of residence are independently associated with anemia status. The study provides valuable insights into the overall anemia prevalence among older adults in India, its underlying causes, and regional differences to lay a strong foundation for making informed decisions toward anemia control in India.

Humans↗

PubMed2006

The associations between socioeconomic status, allostatic load and measures of health in older Taiwanese persons: Taiwan social environment and biomarkers of aging study.

Data from a national representative sample of 1023 elderly and near-elderly Taiwanese were used to explore whether allostatic load is associated with health outcomes and mediates the association between socioeconomic status and health in a non-Western population. The information collected included: demographic characteristics; allostatic load scores; socioeconomic status, measured by education and income; health behaviours; health-related variables, including self-rated health, basic activities of daily living difficulties, instrumental activities of daily living difficulties, and physical activity difficulties. The adjusted prevalent odds ratios of higher allostatic load level were 1.25 (95% CI: 1.00, 1.56) for reporting one level worse in self-rated health and 1.43 (95% CI: 1.14, 1.82) for reporting one more physical activity difficulty. There were significant associations of lower education or less income with worse self-rated health and more difficulties with physical functioning. The associations between education, income and health status are not mediated by the conventional ten-point measure of allostatic load in older Taiwanese adults.

Age Factors↗

PubMed2006

Progestins affect mechanism of estrogen-induced C-reactive protein stimulation.

PURPOSE: To determine whether the mechanisms of C-reactive protein production differ depending on the presence or absence of a progestin in the regimen. SUBJECTS AND METHODS: We examined data from the Postmenopausal Estrogen Progestin Intervention (PEPI) study, a 5-group (3 different combined estrogen-progestin regimens, conjugated equine estrogen-only, and placebo) randomized clinical trial. This substudy included 221 postmenopausal women assigned to active treatment groups who took at least 80% of pills and had stored plasma specimens available to assess 12-month changes in estrone, sex hormone binding globulin, interleukin (IL)-6, and C-reactive protein levels. RESULTS: All treatments resulted in increases in estrone, sex hormone binding globulin, and C-reactive protein at 12 months compared with baseline values. In all progestin-containing groups, 12-month change in IL-6 was positively correlated with 12-month change in C-reactive protein (r between 0.34 and 0.65, each P <.010). By contrast, in the conjugated equine estrogen-only group, 12-month change in IL-6 was negatively correlated with 12-month change in C-reactive protein (r value -0.31, P = .055). In adjusted models predicting 12-month C-reactive protein change, an interaction between change in IL-6 and treatment group was highly significant (P=.0008-P <.0001) for each of the progestin-containing groups compared with the conjugated equine estrogen-only group. In the conjugated equine estrogen-only group, the change in C-reactive protein per unit increase in IL-6 was -0.88, whereas in the progestin-containing groups it ranged from 1.46 to 2.85 (P <.0001 for each comparison with conjugated equine estrogen-only). CONCLUSION: Progestins in combination with conjugated equine estrogen potentiate the IL-6 (inflammatory)-mediated stimulation of C-reactive protein. These findings support the hypothesis that progestins plus estrogen, not estrogen alone, generate C-reactive protein through an inflammatory mechanism.

C-Reactive Protein↗

PubMed2006

Association between serum beta-carotene levels and decline of cognitive function in high-functioning older persons with or without apolipoprotein E 4 alleles: MacArthur studies of successful aging.

BACKGROUND: Growing evidence from animal studies suggests an interaction between antioxidants and apolipoprotein E (APOE) alleles on cognitive functioning. We used data from a 7-year cohort study of high-functioning older persons to explore whether the associations between serum beta-carotene level and subsequent decline of cognitive function differed by APOE 4 genotype. METHODS: Baseline information on sociodemographic characteristics, serum beta-carotene level, inflammation markers, APOE genotype, and cognitive functioning measured by a 9-item Short Portable Mental Status Questionnaire (SPMSQ) was obtained in 455 survivors. Multivariable logistic regression analyses were used to examine the relation between high serum beta-carotene level and risk of SPMSQ score decline in participants with or without APOE 4 alleles, while adjusting for age, sex, race, baseline SPMSQ score, and other covariates. RESULTS: Nine (2%) study participants had homozygous and 97 (21%) had heterozygous APOE 4 alleles. Two hundred forty-nine (55%) had decline of SPMSQ scores during the follow-up. The presence of an APOE 4 allele was associated with higher risk and larger magnitude of SPMSQ score decline. The adjusted odds ratio of high beta-carotene level for cognitive decline was 0.11 (95% confidence interval, 0.02-0.57) in participants with at least one APOE 4 allele and 0.89 (95% confidence interval, 0.54-1.47) among those who were APOE 4 negative. CONCLUSION: Among high-functioning older persons, antioxidants and beta-carotene in particular may offer protection from cognitive decline in persons with greater genetic susceptibility as evidenced by the presence of the APOE 4 allele.

Activities of Daily Living↗

PubMed2006

Alcohol use, comorbidity, and mortality.

OBJECTIVES: To examine the combined influence of alcohol use and comorbidity on 20-year mortality in older adults (average age 66 at the time of the baseline survey). DESIGN: Longitudinal analysis of a national probability sample-based cohort study. SETTING: Data sources were the National Health and Nutrition Examination Survey I (NHANES I), 1971-1974, and the NHANES Epidemiologic Followup Survey, 1992. PARTICIPANTS: Four thousand six hundred ninety-one adults aged 60 and older who provided data on alcohol use. MEASUREMENTS: The prevalence of at-risk drinking in older adults in the United States and the 20-year all-cause mortality risk associated with it. At-risk drinking status was determined from amount of alcohol consumed and comorbidities, using a previously validated method. RESULTS: The prevalence of at-risk drinking in the United States between 1971 and 1974 in older adults was 10% (18% of men, 5% of women). The majority of at-risk drinkers were identified as such because of their use of alcohol in amounts deemed risky in the presence of relevant comorbidities (69%) (e.g., drinking 2-3 drinks per day and having gout or anxiety or taking a medication for pain). In men, at-risk drinking was associated with higher mortality rates than not-at-risk drinking (hazard ratio=1.20, 95% confidence interval=1.01-1.41); abstinence was not associated with greater mortality. In women, neither abstinence nor at-risk drinking was associated with greater mortality rates. CONCLUSION: In this first, large population-based study of older adults examining the mortality risks of alcohol use and comorbidity, at-risk drinking was associated with greater mortality rates in men. These findings suggest that a lower threshold of alcohol use should be recommended for older adults with specific comorbidities to reduce mortality risks.

Aged↗

PubMed2005

Socioeconomic status and C-reactive protein levels in the US population: NHANES IV.

C-reactive protein (CRP), a marker of inflammation, has been identified as a risk factor for cardiovascular disease and mortality. Using data on adults aged 20 and over from the fourth National Health and Nutrition Examination Survey, a nationally representative cross-sectional survey, we examined the association between socioeconomic status and CRP in US adults (N=7634). Socioeconomic variation in CRP occurred only at very high levels of CRP (>10.0 mg/L). There was no significant difference in the prevalence of moderate (1.1-3.0 mg/L) or high values of CRP (3.1-10.0mg/L) by socioeconomic status; however, among those with family income at or below the poverty level, 15.7% had very high levels of CRP (greater than 10.0 mg/L), compared to only 9.1% of those in families above the poverty level. Logistic regression results indicate that acute illness, chronic conditions, and differential health behaviors account for about two-thirds of this association. African Americans, Hispanics, and women were more likely to have high levels of CRP. Obesity was the largest risk factor for every level of CRP above normal. Results suggest that differences in very high CRP may be due to factors beyond acute illness and may also reflect chronic health, behavioral and disease processes associated with low socioeconomic status.

Adult↗

PubMed2005

The effects of hormone therapy on the markers of inflammation and endothelial function and plasma matrix metalloproteinase-9 level in postmenopausal women: the postmenopausal estrogen progestin intervention (PEPI) trial.

OBJECTIVE: The objective of this study was to determine whether oral conjugated equine estrogen (CEE) alone or with one of the three progestin regimens causes changes in biomarkers predictive of adverse cardiovascular events: C-reactive protein (CRP), interleukin-6 (IL-6), intercellular adhesion molecule (ICAM) and matrix metalloproteinase-9 (MMP-9). METHODS AND RESULTS: The analysis included 271 postmenopausal women from the postmenopausal estrogen progestin intervention (PEPI) trial. Plasma levels of biomarkers were measured on frozen samples obtained at baseline, 1- and 3-year follow-up visits. Multivariable linear mixed effects models were used to estimate changes in CRP, IL-6, ICAM and MMP-9 levels from baseline to follow-up visits by treatment groups. Women assigned to CEE only or CEE plus a progestin had 121 and 150% 1-year increase in CRP levels, respectively. In contrast, these treatments caused no significant change in IL-6 levels. Women assigned to CEE with or without a progestin had a 6-8% decline in ICAM and a 26-33% decline in MMP-9. CONCLUSIONS: The linkage between CEE alone or with a progestin and increased cardiovascular events may be associated with a rise in CRP level, but not through the mechanisms of IL-6-mediated inflammation, endothelial dysfunction or increased MMP activity.

C-Reactive Protein↗

PubMed2005

Relationship between subjective social status and measures of health in older Taiwanese persons.

OBJECTIVES: To compare the association between subjective ladder ranking and health measures with the association between objective indices and health measures in older Taiwanese men and women. DESIGN: Cross-sectional study. SETTING: A population-representative sample of elderly and nearly elderly men and women in Taiwan. PARTICIPANTS: The study included 991 participants from the Social Environment and Biomarkers of Aging Study in Taiwan. MEASUREMENTS: The information collected included demographic characteristics; subjective ladder score of SES; objective measures of SES, including education, income, and occupation; health behaviors; health-related variables such as self-rated health, basic activity of daily living difficulties, instrumental activity of daily living (IADL) difficulties, and physical activity difficulties; and depression score. RESULTS: Low ladder score was associated with poorer self-rated health and more reported IADL and physical activity difficulties, even after adjustment for objective measures of SES and other covariates. The multiply adjusted odds ratio for a one-quartile difference in ladder score and worse self-rated health was 1.19 (95% confidence interval=1.06-1.33). The associations between subjective ladder ranking and health status were generally stronger in those who had 6 years or less of education than in those who received more education. CONCLUSION: A simple subjective assessment of one's ranking on the social hierarchy was associated with self-rated health and physical functional status in an older ethnic Chinese population. The associations were independent of the effects of traditional objective measures of SES, such as education, income, and occupation.

Activities of Daily Living↗

PubMed2004

The effects of serum beta-carotene concentration and burden of inflammation on all-cause mortality risk in high-functioning older persons: MacArthur studies of successful aging.

BACKGROUND: It remains unclear to what extent the associations between low serum beta-carotene concentration and increased risk for cardiovascular disease and cancers are attributable to inflammation. The objective of this study was to evaluate simultaneously the effects of serum beta-carotene concentration and inflammation on the subsequent all-cause mortality risk in high-functioning older persons. METHODS: The authors conducted a prospective cohort study using information from 672 participants from the MacArthur Studies of Successful Aging. Baseline information was obtained for serum concentrations of beta-carotene, C-reactive protein, interleukin-6, cholesterols, and albumin; body mass index; waist:hip ratio; prevalent medical conditions; health behaviors; and medications. Sex-specific univariate and multivariate logistic regression analyses were used to study the effects of low beta-carotene, high inflammation burden, or both on 7-year all-cause mortality rates while adjusting for other confounders. RESULTS: The serum beta-carotene concentration was inversely associated with C-reactive protein and interleukin-6 levels. After adjustment for inflammation markers and other covariates, the relative risks for low beta-carotene for the 7-year all-cause mortality risk were 2.30 (95% confidence interval [CI], 1.23 to 4.31) in men and 0.85 (95% CI, 0.42 to 1.75) in women. Compared with men with high beta-carotene levels and low inflammation, the multiply adjusted relative risk for low beta-carotene and high inflammation burden was 3.78 (95% CI, 1.69 to 8.47) in men. CONCLUSIONS: Low levels of serum beta-carotene are independently associated with an increased all-cause mortality risk in older men, even after adjustment for the effects of inflammation and other risk factors. In men, but not women, a synergistic effect occurs between low beta-carotene concentration and high inflammation burden in predicting higher mortality rates.

Aged↗

PubMed2003

Does inflammation or undernutrition explain the low cholesterol-mortality association in high-functioning older persons? MacArthur studies of successful aging.

OBJECTIVES: To explore the effect of inflammation and undernutrition on the association between hypocholesterolemia and higher overall mortality in high-functioning older persons. DESIGN: Prospective cohort study. SETTING: Three U.S. communities. PARTICIPANTS: A cohort of 870 participants from the MacArthur Studies of Successful Aging. MEASUREMENTS: Baseline information was obtained for serum levels of cholesterol, C-reactive protein, interleukin-6, and albumin; body mass index; prevalent medical conditions; health behaviors; and medications. Crude and multivariate logistic regression analyses were used to examine the association between serum total cholesterol levels and 7-year all-cause mortality, while adjusting for potential confounders. RESULTS: In univariate analysis, the risk ratio of low serum total cholesterol level (<169 mg/dL) for 7-year total mortality was 1.90 (95% confidence interval (CI) = 1.18-3.07). The multiple adjusted risk ratios were 1.82 (95% CI = 1.10-3.00) after controlling for markers of inflammation and nutrition and 1.39 (95% CI = 0.80-2.40) after adjustment for additional cardiovascular risk factors. Sex was an important confounding variable that contributed to the observed inverse association between low serum cholesterol and overall mortality in univariate analysis. CONCLUSIONS: Hypocholesterolemia is not an independent risk factor for increased overall mortality in high-functioning community-dwelling older men and women. The association between low total cholesterol and high mortality observed in crude analysis is mainly confounded by common cardiovascular risk factors, rather than underlying inflammation or undernutrition.

Aged↗

PubMed2002

Effects of managed care on the length of time that elderly patients spend with physicians during ambulatory visits: National Ambulatory Medical Care Survey.

OBJECTIVES: To examine the factors related to the length of time that elderly patients spend with physicians during ambulatory visits and explore specifically the association between managed care and visit duration. DESIGN: Cross-sectional analysis of the 1998 National Ambulatory Medical Care Survey. SUBJECTS: Four thousand nine hundred sixty-four office visits to nonfederally employed physicians by elderly patients who had face-to-face contact with physicians and had complete information on variables related to managed care. MEASURES: Information was collected on the characteristics of patient, physician and clinic, visit duration, reasons for visit, diagnoses, clinical services performed, and medications ordered. Measures of managed care included patient's health maintenance organization (HMO) status, requirement of authorization, capitation, and HMO ownership of the clinic. RESULTS: The mean visit duration was 19.2 minutes for elderly patients (27.0 minutes for new patients and 18.3 minutes for established patients; P <0.001). In bivariate analyses, the patient's HMO status was not associated with visit duration, but office visits for patients seen at clinics owned by HMOs were 4.2 minutes shorter than those seen in other settings (P <0.001). In multivariate analyses with mixed-effect models, HMO-owned clinic was an independent predictor for shorter visit duration, after adjusting for other patient, physician, and clinic characteristics and type of service provided. CONCLUSIONS: The effects of managed care on the duration of ambulatory visits by elderly patients appear to be related to the structure of the managed care plan rather than managed care reimbursement per se.

Adult↗

PubMedDate not supplied

Relation of oxytocin to psychological stress responses and hypothalamic-pituitary-adrenocortical axis activity in older women.

OBJECTIVE: Animal research suggests that oxytocin (OT) plays a role in stress responses and that in females, this role is modulated by estrogen. Yet little is known about the relation of OT to human stress responses. This study was conducted to examine the relations between estrogen activity and OT, identify stressors distinctively associated with elevations in OT, and investigate whether OT is related to cardiovascular and hypothalamic-pituitary-adrenocortical (HPA) activity in a laboratory challenge paradigm. METHODS: Seventy-three postmenopausal women who were on hormone therapy (HT) or not completed questionnaires assessing psychological distress and social relationships and then participated in a laboratory stress challenge (Trier Social Stress Task), during which OT, cortisol, and blood pressure were assessed. RESULTS: HT was significantly associated with higher plasma OT. Controlling for HT, elevated plasma OT was significantly associated with gaps in social relationships, with less positive relationships with a primary partner, and with elevated cortisol levels. OT was not associated with stress reactivity or recovery. CONCLUSION: In women, plasma OT signals relationship stress and is associated with elevated cortisol; it does not appear to significantly affect cortisol or blood pressure responses to acute stress.

Aged↗