@article {1488, title = {Incidence of and risk factors for atrial fibrillation in older adults.}, journal = {Circulation}, volume = {96}, year = {1997}, month = {1997 Oct 07}, pages = {2455-61}, abstract = {

BACKGROUND: This study aimed to describe the incidence of atrial fibrillation (AF) among older adults during 3 years of follow-up.

METHODS AND RESULTS: In this cohort study, 5201 adults > or = 65 years old were examined annually on four occasions between June 1989 and May 1993. At baseline, participants answered questionnaires and underwent a detailed examination that included carotid ultrasound, pulmonary function tests, ECG, and echocardiography. Subjects with a pacemaker or AF at baseline (n=357) were excluded. New cases of AF were identified from three sources: (1) annual self-reports, (2) annual ECGs, and (3) hospital discharge diagnoses. Cox proportional-hazards models were used to assess baseline risk factors as predictors of incident AF. Among 4844 participants, 304 developed a first episode of AF during an average follow-up of 3.28 years, for an incidence of 19.2 per 1000 person-years. The onset was strongly associated with age, male sex, and the presence of clinical cardiovascular disease. For men 65 to 74 and 75 to 84 years old, the incidences were 17.6 and 42.7, respectively, and for women, 10.1 and 21.6 events per 1000 person-years. In stepwise models, the use of diuretics, a history of valvular heart disease, coronary disease, advancing age, higher levels of systolic blood pressure, height, glucose, and left atrial size were all associated with an increased risk of AF. The use of beta-blockers and high levels of alcohol use, cholesterol, and forced expiratory volume in 1 second were associated with a reduced risk of AF.

CONCLUSIONS: The incidence of AF in older adults may be higher than estimated by previous population studies. Left atrial size appears to be an important risk factor, and the control of blood pressure and glucose may be important in preventing the development of AF.

}, keywords = {Adult, Aged, Atrial Fibrillation, Blood Glucose, Blood Pressure, Cerebrovascular Disorders, Cohort Studies, Coronary Disease, Electrocardiography, Female, Follow-Up Studies, Hospital Records, Humans, Incidence, Male, Prospective Studies, Risk Factors, United States}, issn = {0009-7322}, author = {Psaty, B M and Manolio, T A and Kuller, L H and Kronmal, R A and Cushman, M and Fried, L P and White, R and Furberg, C D and Rautaharju, P M} } @article {675, title = {Fasting and 2-hour postchallenge serum glucose measures and risk of incident cardiovascular events in the elderly: the Cardiovascular Health Study.}, journal = {Arch Intern Med}, volume = {162}, year = {2002}, month = {2002 Jan 28}, pages = {209-16}, abstract = {

BACKGROUND: The contributions of fasting and 2-hour postchallenge glucose level to cardiovascular events remain ill-defined, especially for nondiabetic adults. This study examined the relative predictive power of fasting and 2-hour glucose level on cardiovascular event risk.

METHODS: A total of 4014 community-dwelling adults 65 years or older who participated in the baseline visit of the Cardiovascular Health Study and who were without treated diabetes or previous myocardial infarction or stroke were eligible for analyses. Participants with treated diabetes at baseline were excluded. Incident myocardial infarction or stroke, or coronary death, was the outcome of interest. Age-, sex-, and race-adjusted proportional hazards regression models described individual and joint associations between baseline measures of fasting and 2-hour postchallenge glucose level and event risk.

RESULTS: There were 764 incident cardiovascular events during 8.5 years of follow-up. Fasting glucose level of 115 mg/dL (6.4 mmol/L) or more was associated with an increased cardiovascular risk (hazard ratio [HR], 1.66 [95\% confidence interval (CI), 1.39-1.98]) in adjusted analyses compared with fasting glucose level less than 115 mg/dL. Two-hour glucose level was associated with a linear risk (HR, 1.02 [95\% CI, 1.00-1.04] per 10 mg/dL [0.6 mmol/L]) that included an additional increase in risk for 2-hour glucose level of 154 mg/dL (8.5 mmol/L) or more (HR, 1.29 [95\% CI, 1.04-1.59]) in adjusted analyses. In joint fasting and 2-hour glucose models, only 2-hour glucose level remained predictive of event risk.

CONCLUSIONS: Two-hour glucose level was better than fasting glucose level alone at identifying older adults at increased risk of major incident cardiovascular events.

}, keywords = {Aged, Blood Glucose, Cardiovascular Diseases, Fasting, Female, Glucose Tolerance Test, Humans, Male, Myocardial Infarction, Predictive Value of Tests, Proportional Hazards Models, Risk Assessment, Stroke}, issn = {0003-9926}, doi = {10.1001/archinte.162.2.209}, author = {Smith, Nicholas L and Barzilay, Joshua I and Shaffer, Douglas and Savage, Peter J and Heckbert, Susan R and Kuller, Lewis H and Kronmal, Richard A and Resnick, Helaine E and Psaty, Bruce M} } @article {791, title = {The association of fasting glucose levels with congestive heart failure in diabetic adults > or =65 years: the Cardiovascular Health Study.}, journal = {J Am Coll Cardiol}, volume = {43}, year = {2004}, month = {2004 Jun 16}, pages = {2236-41}, abstract = {

OBJECTIVES: The purpose of this study was to determine if fasting glucose levels are an independent risk factor for congestive heart failure (CHF) in elderly individuals with diabetes mellitus (DM) with or without coronary heart disease (CHD).

BACKGROUND: Diabetes mellitus and CHF frequently coexist in the elderly. It is not clear whether fasting glucose levels in the setting of DM are a risk factor for incident CHF in the elderly.

METHODS: A cohort of 829 diabetic participants, age > or =65 years, without prevalent CHF, was followed for five to eight years. The Cox proportional hazards modeling was used to determine the risk of CHF by fasting glucose levels. The cohort was categorized by the presence or absence of prevalent CHD.

RESULTS: For a 1 standard deviation (60.6 mg/dl) increase in fasting glucose, the adjusted hazard ratios for incident CHF among participants without CHD at baseline, with or without an incident myocardial infarction (MI) or CHD event on follow-up, was 1.41 (95\% confidence interval 1.24 to 1.61; p < 0.0001). Among those with prevalent CHD at baseline, with or without another incident MI or CHD event on follow-up, the corresponding adjusted hazard ratio was 1.27 (95\% confidence interval 1.02 to 1.58; p < 0.05).

CONCLUSIONS: Among older adults with DM, elevated fasting glucose levels are a risk factor for incident CHF. The relationship of fasting glucose to CHF differs somewhat by the presence or absence of prevalent CHD.

}, keywords = {Aged, Biomarkers, Blood Glucose, Blood Pressure, Coronary Disease, Diabetes Mellitus, Diabetic Angiopathies, Fasting, Female, Follow-Up Studies, Heart Failure, Humans, Incidence, Male, Proportional Hazards Models, Risk Factors, Statistics as Topic, Stroke Volume, Ventricular Function, Left}, issn = {0735-1097}, doi = {10.1016/j.jacc.2003.10.074}, author = {Barzilay, Joshua I and Kronmal, Richard A and Gottdiener, John S and Smith, Nicholas L and Burke, Gregory L and Tracy, Russell and Savage, Peter J and Carlson, Michelle} } @article {914, title = {New-onset diabetes and risk of all-cause and cardiovascular mortality: the Cardiovascular Health Study.}, journal = {Diabetes Care}, volume = {29}, year = {2006}, month = {2006 Sep}, pages = {2012-7}, abstract = {

OBJECTIVE: Cardiovascular risk associated with new-onset diabetes is not well characterized. We hypothesized that risk of all-cause and cardiovascular mortality would be similar among participants with and without new-onset diabetes in the first years of follow-up and rise over time for new-onset diabetes.

RESEARCH DESIGN AND METHODS: The Cardiovascular Health Study (CHS) is a longitudinal study of cardiovascular risk factors in adults aged > or =65 years. We used CHS participants to define a cohort (n = 282) with new-onset diabetes during 11 years of follow-up. New-onset diabetes was defined by initiation of antidiabetes medication or by fasting plasma glucose >125 mg/dl among CHS participants without diabetes at study entry. Three CHS participants without diabetes were matched for age, sex, and race to each participant with new-onset diabetes at the time of diabetes identification (n = 837). Survival analysis provided adjusted hazard ratios (HRs) for all-cause and cardiovascular mortality.

RESULTS: During a median of 5.9 years of follow-up, there were 352 deaths, of which 41\% were cardiovascular. In adjusted analyses, new-onset diabetes was associated with an HR of 1.9 (95\% CI 1.4-2.5) for all-cause and 2.2 (1.4-3.4) for cardiovascular mortality compared with no diabetes. Mortality risks were elevated within 2 years of onset, especially cardiovascular risk (4.3 [95\% CI 1.7-10.8]), and did not increase over time.

CONCLUSIONS: Our findings indicate that there may be a mortality differential soon after diabetes onset in older adults and suggest that long-term macrovascular damage from atherosclerosis may not be primarily responsible for increased risk.

}, keywords = {Aged, Aged, 80 and over, Atherosclerosis, Blood Glucose, Cardiovascular Diseases, Diabetes Complications, Diabetes Mellitus, Follow-Up Studies, Humans, Kaplan-Meier Estimate, Risk Factors, Survival Rate, Time Factors}, issn = {0149-5992}, doi = {10.2337/dc06-0574}, author = {Smith, Nicholas L and Barzilay, Joshua I and Kronmal, Richard and Lumley, Thomas and Enquobahrie, Daniel and Psaty, Bruce M} } @article {952, title = {The relationship of heart rate and heart rate variability to non-diabetic fasting glucose levels and the metabolic syndrome: the Cardiovascular Health Study.}, journal = {Diabet Med}, volume = {24}, year = {2007}, month = {2007 Aug}, pages = {855-63}, abstract = {

BACKGROUND: Increased heart rate (HR) and diminished heart rate variability (HRV) are signs of early cardiovascular autonomic neuropathy. We tested the hypotheses that increased HR and diminished HRV are present in people: (i) with increased fasting glucose (FG) levels not in the range of diabetes mellitus (DM), and (ii) in people with the metabolic syndrome (MetS) independent of elevated FG levels.

METHODS: HR and HRV were determined in 1267 adults (mean age 72 years) who had Holter monitoring and FG measures: 536 had normal FG levels (NORM, FG 4.5-5.5 mmol/l), 363 had mildly impaired FG (IFG-1, FG 5.6-6.0 mmol/l), 182 had significantly impaired FG (IFG-2, FG 6.1-6.9 mmol/l) and 178 had DM (FG > 6.9 mmol/l or use of glucose-lowering agents/insulin). HR and HRV in NORM/IFG-1 was further compared by the number of components of the MetS and compared by the presence or absence of MetS in IFG-2/DM.

RESULTS: HRV indices were more impaired in IFG-2 and DM than in NORM or IFG-1. There were few differences in HRV indices between NORM and IFG-1 or between IFG-2 and DM. In NORM/IFG-1 participants, having > or = 2 components of the MetS was associated with a greater decrease in HRV compared with having no or one components. In IFG-2/DM participants, MetS was associated with decreased HRV compared with no MetS.

CONCLUSIONS: Increased HR and diminished HRV occur in the non-diabetic FG range. Diminished HRV is associated with the MetS, independent of FG levels. Both these results suggest that factors associated with increasing non-diabetic FG levels and the MetS play a role in the onset of cardiac autonomic impairment.

}, keywords = {Aged, Aged, 80 and over, Arrhythmias, Cardiac, Blood Glucose, Fasting, Female, Glucose Intolerance, Heart Rate, Humans, Male, Metabolic Syndrome, Risk Factors}, issn = {0742-3071}, doi = {10.1111/j.1464-5491.2007.02163.x}, author = {Stein, P K and Barzilay, J I and Domitrovich, P P and Chaves, P M and Gottdiener, J S and Heckbert, S R and Kronmal, R A} }