PubMed Health⌕ Search

Biomedical subjects

Joan C Lo

Publications and source records attributed to Joan C Lo.

At least 19 recordsLinked to original sources
PubMed2006

Plasma leptin levels and coronary artery calcification in older adults.

CONTEXT: Leptin is associated with adiposity and insulin resistance and may play a direct role in vascular calcification. It is unclear, however, whether leptin is an independent predictor of atherosclerotic burden. OBJECTIVE: The aim of this study was to examine the association between plasma leptin and coronary artery calcification (CAC) in an ethnically diverse cohort of older adult men and women free of clinical cardiovascular disease. DESIGN: This was a cross-sectional study with data collection between January 2002 and February 2004 as part of the ADVANCE Study. SETTING: The study was conducted at an integrated health care delivery system in Northern California. PARTICIPANTS: Participants included 949 men and women aged 60-69 yr old. INTERVENTIONS: There were no interventions. MAIN OUTCOME MEASURE: The main outcome measure was CAC by multidetector row computed tomography. RESULTS: In ordinal logistic regression, plasma leptin levels were positively associated with extent of CAC independently of age, race/ethnicity, and smoking status in women (odds ratio of higher CAC for the sex-specific upper tertile vs. lower tertile = 1.81; 95% confidence interval, 1.10-3.00) but not in men (odds ratio = 1.29; 95% confidence interval = 0.89-1.86). However, this association was explained by metabolic risk factors and adiposity measures. CONCLUSIONS: Our findings support a role of leptin on vascular calcification in women but, in our sample of older adults, the association between leptin and CAC was not independent of other cardiac risk factors.

Aged↗
PubMed2006

Statin therapy and risks for death and hospitalization in chronic heart failure.

CONTEXT: Whether statin therapy has beneficial effects on clinical outcomes in patients with heart failure is unclear. OBJECTIVE: To evaluate the association between initiation of statin therapy and risks for death and hospitalization among adults with chronic heart failure. DESIGN, SETTING, AND PATIENTS: Propensity-adjusted cohort study of adults diagnosed with heart failure who were eligible for lipid-lowering therapy but had no previous known statin use, within an integrated health care delivery system in northern California between January 1, 1996, and December 31, 2004. Statin use was estimated from filled outpatient prescriptions in pharmacy databases. MAIN OUTCOME MEASURES: All-cause death and hospitalization for heart failure during a median of 2.4 years of follow-up. We examined the independent relationships between statin therapy and risks for adverse events overall and stratified by the presence or absence of coronary heart disease after multivariable adjustment for potential confounders. RESULTS: Among 24,598 adults diagnosed with heart failure who had no prior statin use, those initiating statin therapy (n = 12,648; 51.4%) were more likely to be younger, male, and have known cardiovascular disease, diabetes, and hypertension. There were 8235 patients who died. Using an intent-to-treat approach, incident statin use was associated with lower risks of death (age- and sex-adjusted rate of 14.5 per 100 person-years with statin therapy vs 25.3 per 100 person-years without statin therapy; adjusted hazard ratio, 0.76 [95% confidence interval, 0.72-0.80]) and hospitalization for heart failure (age- and sex-adjusted rate of 21.9 per 100 person-years with statin therapy vs 31.1 per 100 person-years without statin therapy; adjusted hazard ratio, 0.79 [95% confidence interval, 0.74-0.85]) even after adjustment for the propensity to take statins, cholesterol level, use of other cardiovascular medications, and other potential confounders. Incident statin use was associated with lower adjusted risks of adverse outcomes in patients with or without known coronary heart disease. CONCLUSION: Among adults diagnosed with heart failure who had no prior statin use, incident statin use was independently associated with lower risks of death and hospitalization among patients with or without coronary heart disease.

Adult↗
PubMed2006

Value of the sagittal abdominal diameter in coronary heart disease risk assessment: cohort study in a large, multiethnic population.

Whether visceral obesity predicts coronary heart disease (CHD) risk above and beyond overall fatness remains unsettled. Moreover, whether the association between visceral obesity and CHD risk differs by sex, age, race, and overall fatness is poorly understood. The authors conducted a cohort study among 101,765 adult members of Kaiser Permanente of Northern California who underwent multiphasic health checkups between 1965 and 1970. After a median of 12 years and adjustment for age, race, body mass index (BMI), educational level, smoking, alcohol consumption, and hormone replacement therapy (in women), the upper quartile of standing sagittal abdominal diameter, relative to the lowest quartile, was associated with a 1.42-fold increased hazard of CHD in men (95% confidence interval: 1.30, 1.55) and a 1.44-fold increased hazard of CHD in women (95% confidence interval: 1.30, 1.59). Further adjustment for metabolic mediators attenuated the association minimally. Standing sagittal abdominal diameter was a consistent predictor of CHD across racial groups but was more strongly associated with CHD in the younger age group. Joint consideration of BMI/standing sagittal abdominal diameter categories better discriminated risk of CHD compared with use of BMI alone. In conclusion, standing sagittal abdominal diameter was a strong predictor of CHD independently of BMI and added incremental CHD risk prediction at each level of BMI.

Abdomen↗
PubMed2006

Single-dose lopinavir-ritonavir acutely inhibits insulin-mediated glucose disposal in healthy volunteers.

Previously, we found that 4 weeks of treatment with lopinavir-ritonavir did not decrease insulin sensitivity but did increase adiponectin levels. In the present study, a single dose of lopinavir-ritonavir decreases insulin sensitivity but does not alter adiponectin levels. Insulin resistance from protease inhibitors may decrease with prolonged use; an increase in adiponectin levels may mediate this effect.

Adiponectin↗
PubMed2006

Epidemiology and adverse cardiovascular risk profile of diagnosed polycystic ovary syndrome.

CONTEXT: Polycystic ovary syndrome (PCOS) is associated with menstrual and reproductive abnormalities, insulin resistance, and obesity. OBJECTIVE: The objective of this study was to determine the prevalence of diagnosed PCOS and its association with cardiovascular risk factors. SETTING: The study is set in an integrated health care delivery system in northern California. PATIENTS: A total of 11,035 women with PCOS were identified by one or more outpatient diagnoses of PCOS using health plan databases. An age-matched sample of women without PCOS was also selected. OUTCOME MEASURES: Prevalence of PCOS and targeted cardiovascular risk factors [hypertension, dyslipidemia, diabetes mellitus, and body mass index (BMI)] were measured. RESULTS: During 2002-2004, the prevalence of diagnosed PCOS among female members aged 25-34 yr was 2.6% (95% confidence interval 1.6-1.7%). Women with diagnosed PCOS were more likely than those without PCOS to be obese [BMI > or = 30 mg/m(2); odds ratio (OR) 4.21, 3.96-4.47]. Furthermore, PCOS was associated with diabetes (OR 2.45, confidence interval 2.16-2.79), hypertension (OR 1.41, 1.31-1.51) and known dyslipidemia (OR 1.53, 1.39-1.68), even after adjusting for BMI and known confounders. Among women with PCOS, compared with whites, Blacks and Hispanics were more likely and Asians less likely to be obese; Asians and Hispanics were more likely to have diabetes; and Blacks were more likely and Hispanics less likely to have hypertension. CONCLUSIONS: Within a large, community-based population receiving health care, diagnosed PCOS was highly prevalent and associated with a much higher frequency of cardiovascular risk factors that varied by race/ethnicity. Our prevalence estimates likely underestimate the true prevalence of PCOS. Further studies are needed to explore racial/ethnic differences and the extent to which PCOS contributes to future cardiovascular risk.

Adult↗
PubMed2006

The association of genetic polymorphisms in sex hormone biosynthesis and action with insulin sensitivity and diabetes mellitus in women at midlife.

We evaluated associations of insulin sensitivity, metabolic syndrome, and diabetes mellitus with single nucleotide polymorphism (SNP) variants from sex hormone biosynthesis and action in women of 4 races/ethnicities. DNA was extracted from transformed cell samples of 1,538 women in the Study of Women's Health Across the Nation (SWAN). African American, Caucasian, Chinese, and Japanese women in SWAN enrolled in the Sex Steroid Hormone Genetics Protocol from whom fasting glucose and insulin measures (for estimating insulin sensitivity), diabetes status, and metabolic syndrome classification were obtained. SNPs from the genes encoding aromatase (CYP 19), 17beta-hydroxysteroid dehydrogenase (17HSD) type 1, and the estrogen receptors-alpha (ESR1) and -beta (ESR2) were measured. The prevalence of metabolic syndrome was 20% in Chinese women, 22% in Japanese women, 28% in Caucasian women, and 43% in African American women. The prevalence of diabetes was 3% in Chinese women, 4% in Japanese women, 7% in Caucasian women, and 19% in African American women. Significant associations of CYP 19 genotypes and insulin sensitivity were observed in African American, Caucasian, and Japanese women. Selected ESR1 and ESR2 genotypes were associated with insulin sensitivity and metabolic syndrome only in Japanese and Chinese women. The strongest associations related 17HSD genotypes to diabetes in Caucasian women, with odds ratios ranging from 4.4 to 7.5 and confidence intervals that excluded the null value. We observed strong associations between variations in sex hormone biosynthesis and function genes with insulin sensitivity, the metabolic syndrome, and diabetes that varied by race/ethnicity. The strong association of 17HSD and diabetes in Caucasian women has not been previously reported and should be further investigated.

17-Hydroxysteroid Dehydrogenases↗
PubMed2006

Comparative analysis of neonatal morbidity for vaginal and caesarean section deliveries using hospital charge.

AIM: To assess the neonatal morbidity of alternative modes of delivery using economic data. METHODS: Two groups of neonatal morbidity data were extracted according to mode of delivery from inpatient claims on National Health Insurance in Taiwan: uncomplicated vaginal and caesarean section deliveries. Outcome variables included number of infants treated as inpatients, duration of hospital stay, and hospital charge during both the first month and the first year of age. RESULTS: Uncomplicated caesarean section delivery of term infants carried a significant increase either in the first month of life or during the first year after birth in both duration of hospital stay and hospital discharge when compared with uncomplicated vaginal delivery. Neonatal jaundice accounted for the greatest morbidity among term newborns, irrespective of delivery mode, followed by infectious, gastrointestinal and respiratory morbidity. Logistic regression analysis demonstrated that uncomplicated vaginal delivery was associated with skin diseases. Uncomplicated caesarean section delivery was associated with infectious disease and disease of the respiratory, digestive and circulatory systems. CONCLUSION: The findings of this study may provide further information for clinicians and would be an important consideration when advising pregnant women on the preferred route of delivery.

Birth Certificates↗
PubMed2006

Epidemiology of non-dialysis-requiring chronic kidney disease and cardiovascular disease.

PURPOSE OF REVIEW: To review recent literature about the relationship between non-dialysis-requiring chronic kidney disease and cardiovascular disease as well as possible explanatory factors. RECENT FINDINGS: Reduced estimated glomerular filtration rate below 60 ml/min/1.73 m independently predicts the risk of death and cardiovascular events in persons with or without known cardiovascular disease as well as those undergoing coronary or peripheral arterial revascularization. This risk is not linearly associated with level of kidney function. Chronic kidney disease is associated with a larger burden of traditional vascular risk factors but is also linked to abnormalities in a variety of nontraditional pathways such as dysregulation of mineral metabolism and arterial calcification, vessel stiffness and endothelial dysfunction, insulin resistance, inflammation, malnutrition, and anemia, among others. Other novel kidney-specific proteins (e.g. renalase) may play direct mediating roles. The relative contribution of these factors to excess cardiovascular disease in chronic kidney disease remains unclear. SUMMARY: Recent evidence demonstrates the importance of non-dialysis-requiring chronic kidney disease as a potent predictor of cardiovascular disease and its complications. Randomized trials should be performed to determine whether modification of traditional and nontraditional risk factors can reduce incident cardiovascular disease as well as which interventions can optimize treatment outcomes in persons with chronic kidney disease and cardiovascular disease.

Cardiovascular Diseases↗
PubMed2006

The metabolic syndrome and chronic kidney disease.

PURPOSE OF REVIEW: The metabolic syndrome is a constellation of physical and laboratory abnormalities including hypertension, hyperglycemia, hyperlipidemia and abdominal obesity. Over the past decade, the metabolic syndrome has emerged as a critically important risk factor for cardiovascular disease. RECENT FINDINGS: A large population-based cross-sectional analysis (the National Health and Nutrition Evaluation Survey III) found that the presence of the metabolic syndrome was associated with chronic kidney disease, defined as an estimated glomerular filtration rate of less than 60 ml/min per 1.73 m and was also associated with proteinuria. More recently, a prospective cohort study found that the presence of the metabolic syndrome was associated with incident chronic kidney disease by the same definition, even when excluding individuals with diabetes mellitus and hypertension. More studies are required to determine whether the relationship between the metabolic syndrome and chronic kidney disease is mainly mediated by hyperglycemia (with insulin resistance) and hypertension, or other metabolic or hemodynamic factors. SUMMARY: The metabolic syndrome is associated with chronic kidney disease. Efforts aimed at determining the mechanisms underlying this association and strategies for the prevention of chronic kidney disease (or slowing the progression of chronic kidney disease) in affected patients should be research priorities in the future.

Cardiovascular Diseases↗
PubMed2005

The relationship between nucleoside analogue treatment duration, insulin resistance, and fasting arterialized lactate level in patients with HIV infection.

BACKGROUND: Treatment with nucleoside reverse-transcriptase inhibitors (NRTIs) is associated with hyperlactatemia, presumably as a result of NRTI-induced mitochondrial toxicity. We examined the association of NRTI treatment duration and lactate level in human immunodeficiency virus (HIV)-infected patients and assessed the relationship of treatment duration and lactate level with insulin resistance. METHODS: Fasting arterialized venous lactate levels, routine blood chemistry findings, insulin resistance (determined by homeostasis model assessment [HOMA-IR]), percentage of body fat (determined by dual-energy radiographic absorptiometry), and detailed histories of antiretroviral therapy were obtained for 95 HIV-infected individuals. The independent association of NRTI treatment duration and lactate level was examined using multivariable linear regression. RESULTS: Among 95 subjects with a mean age (+/- standard deviation [SD]) of 44 +/- 8 years), 95% had NRTI exposure, with current NRTI use in 83%. The mean (+/- SD) lactate level was 1.24 +/- 0.46 mmol/L (6% had a lactate level > 2 mmol/L). Longer duration of NRTI use was positively associated with lactate level (beta = 0.047; P < .01), as were age, duration of protease inhibitor treatment, and HOMA-IR. Female sex and percentage of body fat were negatively associated with lactate level. After adjustment for age, sex, diabetes, percentage of body fat, and duration of protease inhibitor therapy, an increased duration of NRTI therapy remained significantly associated with lactate level (beta = 0.035; P = .04). However, the addition of HOMA-IR to the adjusted model attenuated the relation between duration of NRTI therapy and lactate level (beta = 0.024; P = .14), whereas HOMA-IR was significantly associated with lactate level (beta = 0.206; P < .01). Furthermore, HOMA-IR was also associated with NRTI treatment duration in adjusted analyses. CONCLUSION: NRTI treatment duration was independently associated with higher lactate level, but this relationship was attenuated after adjusting for HOMA-IR. These data raise the possibility that insulin resistance may be an additional mechanism through which NRTI therapy is related to lactate level.

Adult↗
PubMed2005

Metabolic syndrome and the risk for chronic kidney disease among nondiabetic adults.

The metabolic syndrome is a risk factor for the development of diabetes and cardiovascular disease; however, no prospective studies have examined the metabolic syndrome as a risk factor for chronic kidney disease (CKD). A total of 10,096 nondiabetic participants who were in the Atherosclerosis Risk in Communities study and had normal baseline kidney function composed the study cohort. The metabolic syndrome was defined according to recent guidelines from the National Cholesterol Education Program. Incident CKD was defined as an estimated GFR (eGFR) <60 ml/min per 1.73 m2 at study year 9 among those with an eGFR > or =60 ml/min per 1.73 m2 at baseline. After 9 yr of follow-up, 691 (7%) participants developed CKD. The multivariable adjusted odds ratio (OR) of developing CKD in participants with the metabolic syndrome was 1.43 (95% confidence interval [CI], 1.18 to 1.73). Compared with participants with no traits of the metabolic syndrome, those with one, two, three, four, or five traits of the metabolic syndrome had OR of CKD of 1.13 (95% CI, 0.89 to 1.45), 1.53 (95% CI, 1.18 to 1.98), 1.75 (95% CI, 1.32 to 2.33), 1.84 (95% CI, 1.27 to 2.67), and 2.45 (95% CI, 1.32 to 4.54), respectively. After adjusting for the subsequent development of diabetes and hypertension during the 9 yr of follow-up, the OR of incident CKD among participants with the metabolic syndrome was 1.24 (95% CI, 1.01 to 1.51). The metabolic syndrome is independently associated with an increased risk for incident CKD in nondiabetic adults.

Chronic Disease↗
PubMed2005

Increased prevalence of subclinical and clinical hypothyroidism in persons with chronic kidney disease.

BACKGROUND: Previous studies have suggested a higher prevalence of thyroid abnormalities in persons with end-stage renal disease. However, little is known regarding the epidemiology of thyroid disorders in persons with less severe kidney dysfunction. METHODS: We used data from the Third National Health and Nutrition Examination Survey to examine the prevalence of hypothyroidism (clinical and subclinical) at different levels of estimated glomerular filtration rate (GFR). We used multivariable logistic regression to evaluate the association between GFR and prevalent hypothyroidism. RESULTS: Among 14,623 adult participants with serum creatinine and thyroid function test results, the mean age was 48.7 years, and 52.6% were women. The prevalence of hypothyroidism increased with lower levels of GFR (in units of mL/min/1.73 m(2)), occurring in 5.4% of subjects with GFR >/=90, 10.9% with GFR 60-89, 20.4% with GFR 45-59, 23.0% with GFR 30-44, and 23.1% with GFR <30 (P < 0.001 for trend). Overall, 56% of hypothyroidism cases were considered subclinical. Compared with GFR >/=90 mL/min/1.73 m(2), reduced GFR was associated with an increased risk of hypothyroidism, after adjusting for age, gender, and race/ethnicity: adjusted odds ratio 1.07 (95% confidence interval: 0.86-1.32) for GFR 60-89, 1.57 (1.11-2.22) for GFR 45-59, 1.81 (1.04-3.16) for GFR 30-44, and 1.97 (0.69-5.61) for GFR <30 mL/min/1.73 m(2) (P= 0.008 for trend). CONCLUSION: Among a nationally representative sample of adults, reduced glomerular filtration rate was associated with a higher prevalence of hypothyroidism, with many subclinical cases. Future studies are needed to determine the potential adverse effects of subclinical and clinical hypothyroidism in persons with chronic kidney disease.

Adult↗
PubMed2004

Indinavir increases glucose production in healthy HIV-negative men.

In the absence of HIV infection, changes in adipose tissue and lipid levels, HIV protease inhibitor therapy increases fasting glucose levels,suggestive of hepatic insulin resistance. After 4 weeks of indinavir treatment in nine HIV-negative healthy men, fasting glucose production and glycogenolysis were significantly increased. During the euglycemic hyperinsulinemic clamp, indinavir blunted the ability of insulin to suppress glucose production. Therefore, indinavir worsens hepatic insulin sensitivity, increasing endogenous glucose production.

Blood Glucose↗
PubMed2004

The effects of low-dose growth hormone in HIV-infected men with fat accumulation: a pilot study.

Pharmacologic doses of growth hormone (GH) reduce HIV-associated fat accumulation but may worsen glucose metabolism. We investigated the effects of a low dose of GH (1 mg per day) in HIV-infected men with fat accumulation and found that such treatment reduced total fat and increased lean body mass without significant changes in glucose tolerance or insulin sensitivity. Visceral adipose tissue (VAT) levels did not change significantly for the group as a whole, although a reduction in the VAT level was seen in patients with a greater VAT level at baseline.

Adipose Tissue↗
PubMed2004

Progression of atherosclerosis as assessed by carotid intima-media thickness in patients with HIV infection.

BACKGROUND: HIV-infected patients may be at increased risk for coronary events. The purpose of this study was to identify predictors of carotid intima-media thickness (IMT) in HIV patients at baseline and to measure IMT progression over 1 year. METHODS AND RESULTS: We measured blood lipids, inflammatory markers, and IMT in 148 HIV-infected adults (mean age, 45+/-8 years) and in 63 age- and sex-matched HIV-uninfected control subjects. The mean duration of HIV infection was 11 years, and the median duration of protease inhibitor treatment was 3.3 years. Mean baseline IMT was 0.91+/-0.33 mm in HIV patients and 0.74+/-0.17 mm in control subjects (P=0.0001). Multivariable predictors of baseline IMT in HIV patients were age (P<0.001), LDL cholesterol (P<0.001), cigarette pack-years (P=0.005), Latino race (P=0.062), and hypertension (P=0.074). When the control group was added to the analysis, HIV infection was an independent predictor of IMT (P=0.001). The rate of progression among the 121 HIV patients with a repeated IMT measurement at 1 year was 0.074+/-0.13 mm, compared with -0.006+/-0.05 mm in 27 control subjects (P=0.002). Age (P<0.001), Latino race (P=0.02), and nadir CD4 count < or =200 (P=0.082) were multivariable predictors of IMT progression. CONCLUSIONS: Carotid IMT is higher in HIV patients than in age-matched control subjects and progresses much more rapidly than previously reported rates in non-HIV cohorts. In HIV patients, carotid IMT is associated with classic coronary risk factors and with nadir CD4 count < or =200, suggesting that immunodeficiency and traditional coronary risk factors may contribute to atherosclerosis.

Adult↗