Alka M Kanaya

Kaiser Permanente, Oakland, CA, USA

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Publications (52)344.92 Total impact

  • Article: Type 2 Diabetes and 10-Year Risk of Dementia and Cognitive Impairment Among Older Mexican Americans.
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    ABSTRACT: OBJECTIVE Type 2 diabetes has been linked with increased risk of dementia and cognitive impairment among older adults and with premature mortality in young and middle-aged adults. No studies have evaluated the association between diabetes and dementia among Mexican Americans, a population with a high burden of diabetes. We evaluated the association of diabetes with incidence of dementia and cognitive impairment without dementia (CIND) among older Mexican Americans while accounting for competing risk from death.RESEARCH DESIGN AND METHODS This study included 1,617 participants 60-98 years of age from the Sacramento Area Latino Study on Aging followed up to 10 years from 1998. We evaluated the association between diabetes and dementia/CIND with competing risk regression models.RESULTSParticipants free of dementia/CIND at baseline (n = 1,617) were followed annually up to 10 years. There were 677 (41.9%) participants with diabetes, 159 (9.8%) incident dementia/CIND cases, and 361 (22.3%) deaths. Treated and untreated diabetes (hazard ratio 2.12 [95% CI 1.65-2.73] and 2.15 [1.58-2.95]) and dementia/CIND (2.48 [1.75-3.51]) were associated with an increased risk of death. In models adjusted for competing risk of death, those with treated and untreated diabetes had an increased risk of dementia/CIND (2.05 [1.41-2.97] and 1.55 [0.93-2.58]) compared with those without diabetes.CONCLUSIONS These findings provide evidence that the association between type 2 diabetes and dementia/CIND among Mexican Americans remains strong after accounting for competing risk of mortality. Treatments that modify risk of death among those with diabetes may change future dementia risk.
    Diabetes care 03/2013; · 8.09 Impact Factor
  • Article: Elevated Rates of Diabetes in Pacific Islanders and Asian Subgroups: The Diabetes Study of Northern California (DISTANCE).
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    ABSTRACT: OBJECTIVE We estimated the prevalence and incidence of diabetes among specific subgroups of Asians and Pacific Islanders (APIs) in a multiethnic U.S. population with uniform access to care.RESEARCH DESIGN AND METHODS This prospective cohort analysis included 2,123,548 adult members of Kaiser Permanente Northern California, including 1,704,363 with known race/ethnicity (white, 56.9%; Latino, 14.9%; African American, 8.0%; Filipino, 4.9%; Chinese, 4.0%; multiracial, 2.8%; Japanese, 0.9%; Native American, 0.6%; Pacific Islander, 0.5%; South Asian, 0.4%; and Southeast Asian, Korean, and Vietnamese, 0.1% each). We calculated age-standardized (to the 2010 U.S. population) and sex-adjusted diabetes prevalence at baseline and incidence (during the 2010 calendar year). Poisson models were used to estimate relative risks (RRs).RESULTSThere were 210,632 subjects with prevalent diabetes as of 1 January 2010 and 15,357 incident cases of diabetes identified during 2010. The crude diabetes prevalence was 9.9% and the incidence was 8.0 cases per 1,000 person-years and, after standardizing by age and sex to the 2010 U.S. Census, 8.9% and 7.7 cases per 1,000 person-years. There was considerable variation among the seven largest API subgroups. Pacific Islanders, South Asians, and Filipinos had the highest prevalence (18.3, 15.9, and 16.1%, respectively) and the highest incidence (19.9, 17.2, and 14.7 cases per 1,000 person-years, respectively) of diabetes among all racial/ethnic groups, including minorities traditionally considered high risk (e.g., African Americans, Latinos, and Native Americans).CONCLUSIONS High rates of diabetes among Pacific Islanders, South Asians, and Filipinos are obscured by much lower rates among the large population of Chinese and several smaller Asian subgroups.
    Diabetes care 10/2012; · 8.09 Impact Factor
  • Article: Genome-wide association analysis identifies TYW3/CRYZ and NDST4 loci associated with circulating resistin levels.
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    ABSTRACT: Resistin is a polypeptide hormone that was reported to be associated with insulin resistance, inflammation and risk of type 2 diabetes and cardiovascular disease. We conducted a genome-wide association (GWA) study on circulating resistin levels in individuals of European ancestry drawn from the two independent studies: the Nurses' Health Study (n = 1590) and the Health, Aging and Body Composition Study (n = 1658). Single-nucleotide polymorphisms (SNPs) identified in the GWA analysis were replicated in an independent cohort of Europeans: the Gargano Family Study (n = 659). We confirmed the association with a previously known locus, the RETN gene (19p13.2), and identified two novel loci near the TYW3/CRYZ gene (1p31) and the NDST4 gene (4q25), associated with resistin levels at a genome-wide significant level, best represented by SNP rs3931020 (P = 6.37 × 10(-12)) and SNP rs13144478 (P = 6.19 × 10(-18)), respectively. Gene expression quantitative trait loci analyses showed a significant cis association between the SNP rs3931020 and CRYZ gene expression levels (P = 3.68 × 10(-7)). We also found that both of these two SNPs were significantly associated with resistin gene (RETN) mRNA levels in white blood cells from 68 subjects with type 2 diabetes (both P = 0.02). In addition, the resistin-rising allele of the TYW3/CRYZ SNP rs3931020, but not the NDST4 SNP rs13144478, showed a consistent association with increased coronary heart disease risk [odds ratio = 1.18 (95% CI, 1.03-1.34); P = 0.01]. Our results suggest that genetic variants in TYW3/CRYZ and NDST4 loci may be involved in the regulation of circulating resistin levels. More studies are needed to verify the associations of the SNP rs13144478 with NDST4 gene expression and resistin-related disease.
    Human Molecular Genetics 07/2012; 21(21):4774-80. · 7.64 Impact Factor
  • Article: Oxidative damage, platelet activation, and inflammation to predict mobility disability and mortality in older persons: results from the health aging and body composition study.
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    ABSTRACT: Inflammation, oxidative damage, and platelet activation are hypothesized biological mechanisms driving the disablement process. The aim of the present study is to assess whether biomarkers representing these mechanisms predicted major adverse health-related events in older persons. Data are from 2,234 community-dwelling nondisabled older persons enrolled in the Health Aging and Body Composition study. Biomarkers of lipid peroxidation (ie, urinary levels of 8-iso-prostaglandin F(2α)), platelet activation (ie, urinary levels of 11-dehydro-thromboxane B(2)), and inflammation (serum concentrations of interleukin-6) were considered as independent variables of interest and tested in Cox proportional hazard models as predictors of (severe) mobility disability and overall mortality. The sample's (women 48.0%, whites 64.3%) mean age was 74.6 (SD 2.9) years. During the follow-up (median 11.4 years), 792 (35.5%), 269 (12.0%), and 942 (42.2%) events of mobility disability, severe mobility disability, and mortality occurred, respectively. Only interleukin-6 showed significant independent associations with the onset of all the study outcomes. Higher levels of urinary 8-iso-prostaglandin F(2α) and 11-dehydro-thromboxane B(2) independently predicted increased risk of death (hazard ratio 1.10, 95% confidence interval 1.03-1.19 and hazard ratio 1.14, 95% confidence interval 1.06-1.23, respectively). No significant interactions of gender, race, cardiovascular disease, diabetes, and antiplatelet drugs were detected on the studied relationships. The inflammatory marker interleukin-6 is confirmed to be a robust predictor for the onset of negative health-related events. Participants with higher urinary levels of 8-iso-prostaglandin F(2α) and 11-dehydro-thromboxane B(2) presented a higher mortality risk.
    The Journals of Gerontology Series A Biological Sciences and Medical Sciences 03/2012; 67(6):671-6. · 4.60 Impact Factor
  • Article: Weight loss prevents urinary incontinence in women with type 2 diabetes: results from the Look AHEAD trial.
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    ABSTRACT: We determined the effect of weight loss on the prevalence, incidence and resolution of weekly or more frequent urinary incontinence in overweight/obese women with type 2 diabetes after 1 year of intervention in the Look AHEAD (Action for Health in Diabetes) trial. Women in this substudy (2,739, mean ± SD age 57.9 ± 6.8 years, body mass index 36.5 ± 6.1 kg/m(2)) were randomized into an intensive lifestyle weight loss intervention or a diabetes support and education control condition. At baseline 27% of participants reported urinary incontinence on a validated questionnaire (no significant difference by intensive lifestyle intervention vs diabetes support and education). After 1 year of intervention the intensive lifestyle intervention group in this substudy lost 7.7 ± 7.0 vs 0.7 ± 5.0 kg in the diabetes support and education group. At 1 year fewer women in the intensive lifestyle intervention group reported urinary incontinence (25.3% vs 28.6% in the diabetes support and education group, p = 0.05). Among participants without urinary incontinence at baseline 10.5% of intensive lifestyle intervention and 14.0% of diabetes support and education participants experienced urinary incontinence after 1 year (p = 0.02). There were no significant group differences in the resolution of urinary incontinence (p >0.17). Each kg of weight lost was associated with a 3% reduction in the odds of urinary incontinence developing (p = 0.01), and weight losses of 5% to 10% reduced these odds by 47% (p = 0.002). Moderate weight loss reduced the incidence but did not improve the resolution rates of urinary incontinence at 1 year among overweight/obese women with type 2 diabetes. Weight loss interventions should be considered for the prevention of urinary incontinence in overweight/obese women with diabetes.
    The Journal of urology 03/2012; 187(3):939-44. · 4.02 Impact Factor
  • Article: Thyroid function and prevalent and incident metabolic syndrome in older adults: the Health, Ageing and Body Composition Study.
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    ABSTRACT: Both subclinical hypothyroidism and the metabolic syndrome have been associated with increased risk of coronary heart disease events. It is unknown whether the prevalence and incidence of metabolic syndrome is higher as TSH levels increase, or in individuals with subclinical hypothyroidism. We sought to determine the association between thyroid function and the prevalence and incidence of the metabolic syndrome in a cohort of older adults. Data were analysed from the Health, Ageing and Body Composition Study, a prospective cohort of 3075 community-dwelling US adults. Two thousand one hundred and nineteen participants with measured TSH and data on metabolic syndrome components were included in the analysis. TSH was measured by immunoassay. Metabolic syndrome was defined per revised ATP III criteria. At baseline, 684 participants met criteria for metabolic syndrome. At 6-year follow-up, incident metabolic syndrome developed in 239 individuals. In fully adjusted models, each unit increase in TSH was associated with a 3% increase in the odds of prevalent metabolic syndrome (OR, 1.03; 95% CI, 1.01-1.06; P = 0.02), and the association was stronger for TSH within the normal range (OR, 1.16; 95% CI, 1.03-1.30; P = 0.02). Subclinical hypothyroidism with a TSH > 10 mIU/l was significantly associated with increased odds of prevalent metabolic syndrome (OR, 2.3; 95% CI, 1.0-5.0; P = 0.04); the odds of incident MetS was similar (OR 2.2), but the confidence interval was wide (0.6-7.5). Higher TSH levels and subclinical hypothyroidism with a TSH > 10 mIU/l are associated with increased odds of prevalent but not incident metabolic syndrome.
    Clinical Endocrinology 12/2011; 76(6):911-8. · 3.17 Impact Factor
  • Article: F2-isoprostanes and adiposity in older adults.
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    ABSTRACT: We examined whether a systemic marker of oxidative stress, F(2)-isoprostanes (F(2)-IPs), was associated with total and regional adiposity, adipocytokines, and change in adiposity. Using data from 726 participants enrolled in the Health, Aging, and Body Composition (Health ABC) study, F(2)-IPs and adipocytokines were measured from baseline plasma samples. Total adiposity was measured by whole-body dual-energy X-ray absorptiometry and regional adiposity by abdominal and thigh computed tomography scans at baseline and 5-year follow-up. ANOVA models were estimated to examine associations between F(2)-IP tertiles and baseline adiposity and changes in body composition. Median F(2)-IPs was 54.3 pg/ml; women had significantly higher levels than men (61.5 vs. 48.9 pg/ml, P < 0.001). F(2)-IPs were associated with higher levels of adiponectin, leptin, and tumor necrosis factor-α (TNF-α). Positive associations were found between F(2)-IPs and all measures of total and regional adiposity among women. In linear regression models, adipocytokines mediated associations among women. Over 5 years of follow-up, women in the highest vs. lowest F(2)-IP tertile exhibited significant loss of weight (lowest tertile: -1.1 kg, highest tertile: -2.7 kg, P < 0.05). In conclusion, F(2)-IPs were associated with measures of total and regional adiposity in women alone and these associations were partially explained by adipocytokines. F(2)-IPs predicted loss of total adiposity over time among women.
    Obesity 04/2011; 19(4):861-7. · 4.28 Impact Factor
  • Article: Adipokines and the risk of fracture in older adults.
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    ABSTRACT: Adiponectin and leptin are adipokines that influence bone metabolism in vitro and in animal models. However, less is known about the longitudinal association of leptin and adiponectin with fracture. We tested the hypothesis that low leptin and high adiponectin levels are each individually associated with fracture risk in a prospective cohort study in Memphis and Pittsburgh among 3075 women and men aged 70 to 79 years from the Health Aging and Body Composition (Health ABC) study. There were 406 incident fractures (334 nonvertebral and 72 vertebral) over a mean of 6.5 ± 1.9 years. Cox regression was used to estimate the hazard ratios for fracture. Sex modified the association between adiponectin and fracture (p = .025 for interaction). Men with the highest adiponectin level (tertile 3) had a 94% higher risk of fracture [hazard ratio (HR) = 1.94; 95% confidence interval (CI) 1.20-3.16] compared with the lowest tertile (tertile 1; p = .007 for trend) after adjusting age, race, body mass index (BMI), education, diabetes, weight change, and hip bone mineral density (BMD). Among women, after adjusting for age and race, this association was no longer significant (p = .369 for trend). Leptin did not predict fracture risk in women (p = .544 for trend) or men (p = .118 for trend) in the multivariate models. Our results suggest that adiponectin, but not leptin, may be a novel risk factor for increased fracture risk independent of body composition and BMD and that these relationships may be influenced by sex. More research is needed to understand the physiologic basis underlying these sex differences.
    Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research 02/2011; 26(7):1568-76. · 6.04 Impact Factor
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    Article: Heterogeneity of diabetes outcomes among asians and pacific islanders in the US: the diabetes study of northern california (DISTANCE).
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    ABSTRACT: Ethnic minorities with diabetes typically have lower rates of cardiovascular outcomes and higher rates of end-stage renal disease (ESRD) compared with whites. Diabetes outcomes among Asian and Pacific Islander subgroups have not been disaggregated. We performed a prospective cohort study (1996-2006) of patients enrolled in the Kaiser Permanente Northern California Diabetes Registry. There were 64,211 diabetic patients, including whites (n = 40,286), blacks (n = 8,668), Latinos (n = 7,763), Filipinos (n = 3,572), Chinese (n = 1,823), Japanese (n = 951), Pacific Islanders (n = 593), and South Asians (n = 555), enrolled in the registry. We calculated incidence rates (means ± SD; 7.2 ± 3.3 years follow-up) and created Cox proportional hazards models adjusted for age, educational attainment, English proficiency, neighborhood deprivation, BMI, smoking, alcohol use, exercise, medication adherence, type and duration of diabetes, HbA(1c), hypertension, estimated glomerular filtration rate, albuminuria, and LDL cholesterol. Incidence of myocardial infarction (MI), congestive heart failure, stroke, ESRD, and lower-extremity amputation (LEA) were age and sex adjusted. Pacific Islander women had the highest incidence of MI, whereas other ethnicities had significantly lower rates of MI than whites. Most nonwhite groups had higher rates of ESRD than whites. Asians had ~60% lower incidence of LEA compared with whites, African Americans, or Pacific Islanders. Incidence rates in Chinese, Japanese, and Filipinos were similar for most complications. For the three macrovascular complications, Pacific Islanders and South Asians had rates similar to whites. Incidence of complications varied dramatically among the Asian subgroups and highlights the value of a more nuanced ethnic stratification for public health surveillance and etiologic research.
    Diabetes care 02/2011; 34(4):930-7. · 8.09 Impact Factor
  • Article: Body fat distribution and inflammation among obese older adults with and without metabolic syndrome.
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    ABSTRACT: The protective mechanisms by which some obese individuals escape the detrimental metabolic consequences of obesity are not understood. This study examined differences in body fat distribution and adipocytokines in obese older persons with and without metabolic syndrome. Additionally, we examined whether adipocytokines mediate the association between body fat distribution and metabolic syndrome. Data were from 729 obese men and women (BMI ≥ 30 kg/m(2)), aged 70-79 participating in the Health, Aging and Body Composition (Health ABC) study. Thirty-one percent of these obese men and women did not have metabolic syndrome. Obese persons with metabolic syndrome had significantly more abdominal visceral fat (men: P = 0.04; women: P < 0.01) and less thigh subcutaneous fat (men: P = 0.09; women: P < 0.01) than those without metabolic syndrome. Additionally, those with metabolic syndrome had significantly higher levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and plasminogen activator inhibitor-1 (PAI-1) than individuals without metabolic syndrome. Per standard deviation higher in visceral fat, the likelihood of metabolic syndrome significantly increased in women (odds ratio (OR): 2.16, 95% confidence interval (CI): 1.59-2.94). In contrast, the likelihood of metabolic syndrome decreased in both men (OR: 0.56, 95% CI: 0.39-0.80) and women (OR: 0.49, 95% CI: 0.34-0.69) with each standard deviation higher in thigh subcutaneous fat. These associations were partly mediated by adipocytokines; the association between thigh subcutaneous fat and metabolic syndrome was no longer significant in men. In summary, metabolically healthy obese older persons had a more favorable fat distribution, characterized by lower visceral fat and greater thigh subcutaneous fat and a more favorable inflammatory profile compared to their metabolically unhealthy obese counterparts.
    Obesity 12/2010; 18(12):2354-61. · 4.28 Impact Factor
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    Article: Asian Americans and obesity in California: a protective effect of biculturalism.
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    ABSTRACT: Prior studies comparing US-born and foreign-born Asian Americans have shown that birth in the US conveys greater risk of obesity. Our study investigates whether retention of Asian culture might be protective for obesity despite acculturation to US lifestyle. We classified self-identified Asian American respondents of the California Health Interview Survey as traditional, bicultural, and acculturated using nativity and language proficiency in English and Asian language. We then examined the association of acculturation with overweight/obesity (BMI ≥ 25 kg/m²) in a multivariate regression model. Acculturated respondents had higher adjusted odds of being overweight/obese than bicultural respondents (2.13 [1.40-3.23] for men, 3.28 [2.14-5.04] for women), but bicultural respondents had similar odds of being overweight/obese as traditional respondents (.98 [.69-1.41] for men, .72 [.50-1.05] for women). Among the bicultural, second and first generation respondents were equally likely to be overweight/obese. Biculturalism in Asian Americans as measured by Asian language retention appears protective against obesity. Further research is needed to understand the mechanisms underlying this association.
    Journal of Immigrant and Minority Health 12/2010; 13(2):276-83. · 1.16 Impact Factor
  • Article: Fat infiltration of muscle, diabetes, and clinical fracture risk in older adults.
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    ABSTRACT: Older adults with type 2 diabetes are at higher risk for fracture compared with nondiabetic adults after adjustment for their higher bone mineral density. Infiltration of muscle by fat predicts increased risk of hip fracture. We investigated whether fat infiltration of muscle, which is greater in diabetic adults, is associated with all clinical fracture and whether it accounts for the increased fracture risk in those with diabetes. Data were analyzed from the Health, Aging, and Body Composition Study, a cohort of community-dwelling adults aged 70-79 yr. Glucose metabolism status and x-ray attenuation of thigh muscle were determined at baseline for 2762 participants. During a mean 8.2 ± 2.3 yr follow-up, 331 participants reported at least one clinical fracture. Fat infiltration of muscle was higher in those with diabetes or impaired glucose metabolism than in those with normal glucose metabolism (P < 0.001). Fat infiltration of muscle was independently associated with a 19% increased risk of incident clinical fracture (multivariate hazard ratio = 1.19; 95% confidence interval = 1.04-1.36); this association did not differ across glucose metabolism groups (P for interaction = 0.65). As previously reported, diabetes was associated with a greater fracture risk compared with normal glucose metabolism (hazard ratio = 1.42; 95% confidence interval = 1.07-1.89) after adjustment for bone mineral density, but further adjustment for fat infiltration of muscle did not attenuate this association. Fat infiltration of muscle predicts clinical fracture in older adults. Although fat infiltration of muscle is higher among those with diabetes, it does not account for their increased fracture risk.
    The Journal of clinical endocrinology and metabolism 11/2010; 95(11):E368-72. · 6.50 Impact Factor
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    Article: Higher protein intake is associated with diabetes risk in South Asian Indians: the Metabolic Syndrome and Atherosclerosis in South Asians Living in America (MASALA) study.
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    ABSTRACT: Despite a high prevalence of type 2 diabetes in South Asian Indians, the impact of diet in this high-risk ethnic group has not been fully explored. The association of macronutrient intake and diabetes in South Asian Indians was examined in this cross-sectional study. A population-based cohort of 146 South Asian Indians aged 45-79 years without existing cardiovascular disease living in the San Francisco Bay Area was recruited between August 2006 and October 2007. Macronutrient intake was assessed with a food-frequency questionnaire developed and validated in South Asians. Diabetes was defined by use of a hypoglycemic medication, a fasting plasma glucose level > or =126 mg/dL, or a 2-hour post-challenge glucose level > or =200 mg/dL. The association between energy-adjusted macronutrient intake and diabetes was explored using multivariable logistic regression models. Forty-one (28%) participants had type 2 diabetes; 20 were unaware of this diagnosis and were classified as having diabetes by laboratory testing. In a model fully adjusted for age, sex, waist circumference, and hypertension, there was a 70% increase in the odds of diabetes per standard deviation in gram of protein intake/day (standardized OR 1.70 [95% CI 1.08, 2.68], p = 0.02). There was a trend toward increased protein intake and diabetes in the subset of participants with previously unknown, laboratory-diagnosed diabetes. Results did not vary significantly by sex, body mass index, or dietary pattern. Higher level of protein intake was associated with increased odds of diabetes in this cohort of South Asian Indians. Diet may be a modifiable lifestyle factor in this high-risk ethnic group.
    Journal of the American College of Nutrition 04/2010; 29(2):130-5. · 2.29 Impact Factor
  • Article: Association of glucose measures with total and coronary heart disease mortality: does the effect change with time? The Rancho Bernardo Study.
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    ABSTRACT: To compare the associations of three glucose measures with coronary heart disease (CHD) and total mortality and to examine how these associations changed over time. Prospective study of 1774 adults (median age 68 years, 56% female). Fasting plasma glucose (FPG), 2h post-challenge glucose (2hPG), and glycohemoglobin (GHb) were obtained in 1984-1987. Mortality data was obtained for all participants. Multivariable Cox models examined the association of baseline glucose measures with mortality during sequential periods of follow-up (0-6, 7-12, and 13-18 years), adjusting for age, sex, blood pressure, LDL-cholesterol, smoking, exercise, and aspirin use. 854 (48%) participants died during follow-up. In adjusted models, only GHb was associated with total mortality over the entire 18 years (p=0.007). In analyses of mortality in successive six year time intervals, the association of GHb and total mortality was only significant in years 0-6. For each 1% increase in GHb, the hazard ratio for death in years 0-6 was 1.14 (95% CI 1.01-1.30, p=0.04) and the hazard ratio for CHD death was 1.26 (95% CI 1.03-1.55, p=0.02). Stratification by sex and exclusion of participants with diabetes did not change our results. Higher levels of GHb were associated with increased total and CHD mortality within the first six years independent of cardiac risk factors. Though further research is needed, this supports the hypothesis that early glycemic control may affect mortality outcomes.
    Diabetes research and clinical practice 09/2009; 86(1):67-73. · 2.16 Impact Factor
  • Article: Association between oxidized LDL, obesity and type 2 diabetes in a population-based cohort, the Health, Aging and Body Composition Study.
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    ABSTRACT: Accumulating evidence suggests a cross-sectional association between oxidative stress and type 2 diabetes (T2D). Systemic oxidative stress, as measured by oxidized LDL (oxLDL), has been correlated with visceral fat. We examined the relationship between oxLDL, and T2D- and obesity-related traits in a bi-racial sample of 2985 subjects at baseline and after 7 years of follow-up. We examined six T2D-related traits (T2D status, HbA(1c), fasting glucose, insulin, adiponectin and HOMA-IR) as well as six obesity-related traits (obesity status, BMI, leptin, % body fat, visceral and subcutaneous fat mass) using logistic and linear regression models. In all subjects at baseline, oxLDL was positively associated with T2D (OR = 1.3, 95% CI:1.1-1.5), fasting glucose (ss = 0.03 +/- 0.006), HbA(1c) (ss = 0.02 +/- 0.004), fasting insulin (ss = 0.12 +/- 0.02), HOMA-IR (ss = 0.13 +/- 0.02) and negatively with adiponectin (ss = -0.16 +/- 0.03), (all p < 0.001). The strength and magnitude of these associations did not differ much between blacks and whites. In both blacks and whites, oxLDL was also associated with obesity (OR = 1.3, 95% CI:1.1-1.4) and three of its related traits (ss = 0.60 +/- 0.14 for BMI, ss = 0.74 +/- 0.17 for % body fat, ss = 0.29 +/- 0.06 for visceral fat; all p < 0.001). Furthermore, of four traits measured after 7 years of follow-up (fasting glucose, HbA1c, BMI and % fat), their relationship with oxLDL was similar to baseline observations. No significant association was found between oxLDL and incident T2D. Interestingly, oxLDL was significantly associated with % change in T2D- and obesity-related traits in whites but not in blacks. Our data suggest that systemic oxidative stress may be a novel risk factor for T2D and obesity.
    Diabetes/Metabolism Research and Reviews 09/2009; 25(8):733-9. · 3.37 Impact Factor
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    Article: Prevalence and risk factors for urinary incontinence in overweight and obese diabetic women: action for health in diabetes (look ahead) study.
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    ABSTRACT: OBJECTIVE To determine the prevalence and risk factors for urinary incontinence among different racial/ethnic groups of overweight and obese women with type 2 diabetes. RESEARCH DESIGN AND METHODS Cross-sectional analysis of baseline data from the Action for Health in Diabetes (Look AHEAD) study, a randomized clinical trial with 2,994 overweight/obese women with type 2 diabetes. RESULTS Weekly incontinence (27%) was reported more often than other diabetes-associated complications, including retinopathy (7.5%), microalbuminuria (2.2%), and neuropathy (1.5%). The prevalence of weekly incontinence was highest among non-Hispanic whites (32%) and lowest among African Americans (18%), and Asians (12%) (P < 0.001). Asian and African American women had lower odds of weekly incontinence compared with non-Hispanic whites (75 and 55% lower, respectively; P < 0.001). Women with a BMI of > or =35 kg/m(2) had a higher odds of overall and stress incontinence (55-85% higher; P < 0.03) compared with that for nonobese women. Risk factors for overall incontinence, as well as for stress and urgency incontinence, included prior hysterectomy (40-80% increased risk; P < 0.01) and urinary tract infection in the prior year (55-90% increased risk; P < 0.001). CONCLUSIONS Among overweight and obese women with type 2 diabetes, urinary incontinence is highly prevalent and far exceeds the prevalence of other diabetes complications. Racial/ethnic differences in incontinence prevalence are similar to those in women without diabetes, affecting non-Hispanic whites more than Asians and African Americans. Increasing obesity (BMI > or =35 kg/m(2)) was the strongest modifiable risk factor for overall incontinence and stress incontinence in this diverse cohort.
    Diabetes care 06/2009; 32(8):1391-7. · 8.09 Impact Factor
  • Article: Plasma oxidized low-density lipoprotein levels and arterial stiffness in older adults: the health, aging, and body composition study.
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    ABSTRACT: Arterial stiffness is a prominent feature of vascular aging and is strongly related to cardiovascular disease. Oxidized low-density lipoprotein (ox-LDL), a key player in the pathogenesis of atherosclerosis, may also play a role in arterial stiffening, but this relationship has not been well studied. Thus, we examined the cross-sectional association between ox-LDL and aortic pulse wave velocity (aPWV), a marker of arterial stiffness, in community-dwelling older adults. Plasma ox-LDL levels and aPWV were measured in 2295 participants (mean age: 74 years; 52% female; 40% black) from the Health, Aging, and Body Composition Study. Mean aPWV significantly increased across tertiles of ox-LDL (tertile 1: 869+/-376 cm/s; tertile 2: 901+/-394 cm/s; tertile 3: 938+/-415 cm/s; P=0.002). In multivariate analyses, ox-LDL remained associated with aPWV after adjustment for demographics and traditional cardiovascular disease risk factors (P=0.008). After further adjustment for hemoglobin A1c, abdominal visceral fat, antihypertensive and antilipemic medications, and C-reactive protein, the association with ox-LDL was attenuated but remained significant (P=0.01). Results were similar when ox-LDL was expressed in absolute (milligrams per deciliter) or relative amounts (percentage of low-density lipoprotein). Moreover, individuals in the highest ox-LDL tertile were 30% to 55% more likely to have high arterial stiffness, defined as aPWV >75th percentile (P<or=0.02). In conclusion, we found that, among elderly persons, elevated plasma ox-LDL levels were associated with higher arterial stiffness, independent of cardiovascular disease risk factors. These data suggest that ox-LDL may be related to the pathogenesis of arterial stiffness.
    Hypertension 04/2009; 53(5):846-52. · 6.21 Impact Factor
  • Article: Total and regional adiposity and cognitive change in older adults: The Health, Aging and Body Composition (ABC) study.
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    ABSTRACT: To investigate whether total and/or regional adiposity measured by anthropometry and radiographic studies influences cognitive decline in older adults and whether this association is explained by hormones and inflammatory factors known to be secreted by adipose tissue. Prospective cohort study. Two clinical centers. Three thousand fifty-four elderly individuals enrolled in the Health ABC Study. Adiposity measures included body mass index, waist circumference, sagittal diameter, total fat mass by dual-energy x-ray absorptiometry, and subcutaneous and visceral fat by abdominal computed tomography. We examined the association between baseline body fat measures and change in Modified Mini-Mental State Examination (3MS) score, sequentially adjusting for confounding and mediating variables, including comorbid diseases, adipocytokines, and sex hormones. Main Outcome Measure Scores from the 3MS, administered at the first, third, fifth, and eighth annual clinical examinations. All baseline adiposity measures varied significantly by sex. In mixed-effects models, the association between total and regional adiposity and change in 3MS score varied significantly by sex, with the highest adiposity tertile being associated with greater cognitive declines in men (for each adiposity measure, P < .05) but not in women (for interaction, P < .05). Total fat mass was significantly associated with greater change in 3MS scores among men (lowest tertile, -1.6; middle tertile, -2.2; highest tertile, -2.7; P = .006), even after adjusting for mediators. Higher levels of all adiposity measures were associated with worsening cognitive function in men after controlling for metabolic disorders, adipocytokines, and sex hormone levels. Conversely, there was no association between adiposity and cognitive change in women.
    Archives of neurology 03/2009; 66(3):329-35. · 6.31 Impact Factor
  • Article: Urinary incontinence among women with type 1 diabetes--how common is it?
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    ABSTRACT: We compared the prevalence, level of bother and effect on daily activities of urinary incontinence among women with type 1 diabetes enrolled in the Epidemiology of Diabetes Interventions and Complications study to a population based sample of women with normal glucose. We performed a cross-sectional analysis of women with type 1 diabetes and normal glucose tolerance using 2 study populations. The Diabetes Control and Complications Trial cohort followup, Epidemiology of Diabetes Interventions and Complications, began in 1994. In 2004 women participants (550) completed a self-administered questionnaire on urinary incontinence. Our primary outcome was weekly or greater incontinence, overall and by type. Prevalence of urinary incontinence was compared to a subgroup of women with normal glucose in the 2001 to 2002 National Health and Nutrition Examination Survey (NHANES). Overall 65% of women with type 1 diabetes reported any urinary incontinence (17% reported weekly incontinence). Nearly 40% of these women were greatly bothered by their incontinence and 9% believed it affected their day-to-day activities. Women with type 1 diabetes had a nearly 2-fold greater prevalence of weekly urge incontinence compared to those without diabetes in the NHANES cohort (8.8% vs 4.5%, p = 0.01). Urinary incontinence is common in women with type 1 diabetes and the prevalence of weekly urge incontinence is far greater compared to that in women with normal glucose levels. Moreover, the prevalence of urinary incontinence in women with type 1 diabetes was greater than that of neuropathy, retinopathy and nephropathy. These findings highlight the importance of screening for urinary incontinence among women with type 1 diabetes. Studies examining factors associated with urinary incontinence in women with type 1 diabetes are warranted.
    The Journal of urology 02/2009; 181(3):1224-30; discussion 1230. · 4.02 Impact Factor
  • Article: Adiponectin and inducible ischemia in patients with stable coronary heart disease: data from the Heart and Soul study.
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    ABSTRACT: Elevated concentrations of adiponectin are associated with a favorable metabolic profile but also with adverse cardiovascular outcomes. This apparent discrepancy has raised questions about whether adiponectin is associated with an increased or decreased risk of coronary heart disease (CHD). We sought to determine whether higher adiponectin levels are associated with exercise-induced ischemia in patients with stable CHD. We measured total serum adiponectin concentrations and evaluated exercise-induced ischemia by stress echocardiography in a cross-sectional study of 899 outpatients with documented stable CHD. Of these, 217 (24%) had inducible ischemia. Although adiponectin levels correlated negatively with diabetes prevalence, body mass index, serum insulin, fasting glucose, low-density lipoprotein cholesterol, and triglycerides and positively with high-density lipoprotein cholesterol (all P<0.005), elevated adiponectin concentrations were also associated with a greater risk of inducible ischemia. Each standard deviation (0.08 microg/mL) increase in log adiponectin was associated with a 35% greater odds of inducible ischemia (unadjusted odds ratio 1.35; 95% confidence interval 1.15-1.57; P=0.0002). Although attenuated, this association remained present after multivariable adjustment for traditional cardiovascular risk factors and other measures of cardiac function (adjusted odds ratio 1.21; 95% confidence interval 1.02-1.43; P=0.03). Elevated concentrations of adiponectin are independently associated with inducible ischemia in patients with stable CHD. These findings raise the possibility that the presence of chronic inducible ischemia may alter the cardio-protective effects afforded by adiponectin secretion in the healthy population.
    Atherosclerosis 11/2008; 205(1):233-8. · 3.79 Impact Factor

Institutions

  • 2012
    • Kaiser Permanente
      Oakland, CA, USA
  • 2009–2012
    • California Polytechnic State University, San Luis Obispo
      • Department of Kinesiology
      San Luis Obispo, CA, USA
    • University of Michigan
      Ann Arbor, MI, USA
    • San Francisco VA Medical Center
      San Francisco, CA, USA
  • 2011
    • CSU Mentor
      Long Beach, CA, USA
  • 2008–2010
    • National Institute on Aging
      • Laboratory of Epidemiology, Demography and Biometry (LEDB)
      Baltimore, MD, USA
  • 2002–2010
    • University of California, San Francisco
      • • Division of Hospital Medicine
      • • Division of General Internal Medicine
      • • Department of Obstetrics, Gynecology and Reproductive Sciences
      • • Department of Epidemiology and Biostatistics
      San Francisco, CA, USA
  • 2006
    • University of California, Berkeley
      • School of Public Health
      Berkeley, CA, USA
    • George Washington University
      Washington, D. C., DC, USA
  • 2004–2006
    • Wake Forest School of Medicine
      • • Department of Internal Medicine
      • • Sticht Center on Aging
      Winston-Salem, NC, USA
    • Social & Scientific Systems
      Silver Spring, MD, USA
  • 2005
    • University of Maryland, College Park
      • Department of Nutrition and Food Science
      College Park, MD, USA