Postchallenge hyperglycemia and mortality in a national sample of U.S. adults

OBJECTIVE: Although postchallenge hyperglycemia is a well-established feature of type 2 diabetes, its association with risk of mortality is uncertain. Therefore, the aim of this study was to assess the independent association of fasting and 2-h glucose levels with all-cause and cardiovascular disease (CVD) mortality. RESEARCH DESIGN AND METHODS: We analyzed data from the Second National Health and Nutrition Examination Survey (NHANES II) Mortality Study, a prospective cohort study of U.S. adults examined in the NHANES II, and focused on the 3,092 adults aged 30-74 years who underwent an oral glucose tolerance test at baseline (1976-1980). Deaths were identified from U.S. national mortality files from 1976 to 1992. To account for the complex survey design, we used SUDAAN statistical software for weighted analysis. RESULTS: Compared with their normoglycemic counterparts (fasting glucose [FG] < 7.0 and 2-h glucose < 7.8 mmol/l), adults with fasting and postchallenge hyperglycemia (FG > or =7.0 and 2-h glucose > or =11.1 mmol/l) had a twofold higher risk of death after 16 years of follow-up (age- and sex-adjusted relative hazard [RH] 2.1, 95% CI 1.4-3.2). However, adults with isolated postchallenge hyperglycemia (FG < 7.0 and 2-h glucose > or =11.1 mmol/l) were also at higher risk of death (1.6, 1.0-2.6). In proportional hazards analysis, FG (fully adjusted RH 1.10 per 1 SD; 95% CI 1.01, 1.22) and 2-h glucose (1.14, 1.00-1.29) showed nearly identical predictive value for mortality. Similar trends were observed for CVD mortality. CONCLUSIONS: These results suggest that postchallenge hyperglycemia is associated with increased risk of all-cause and CVD mortality independently of other CVD risk factors.     

Correlates of physical activity in a sample of older adults with type 2 diabetes.

OBJECTIVE: Physical activity is integral to the management of type 2 diabetes. Unfortunately, the majority of adults with type 2 diabetes do not regularly engage in physical activity. The purpose of this study was to assess physical activity behavior and its correlates (i.e., physical activity knowledge, barriers, and performance and outcome expectations) in older adults with type 2 diabetes. RESEARCH DESIGN AND METHODS: A subgroup of 260 adults with type 2 diabetes was identified from a larger stratified random sample of adults aged > or = 55 years. Participants completed an interviewer-administered survey designed from focus group findings and social learning theory. RESULTS: The majority of the respondents (54.6%) reported 0 min of weekly physical activity. This was especially true of older female respondents. Performance expectation scores were lower among respondents who were in the oldest age-group, namely, white women. Physical activity knowledge varied by age-group, and barriers to physical activity were prevalent in all groups. The following are significant correlates of reported weekly physical activity: younger age, more education, fewer motivational barriers, and greater perceived health and performance expectations. CONCLUSIONS: Given the importance of physical activity to diabetes management, the low prevalence of physical activity found in this and other studies should raise concerns among clinicians. Future research to identify predictors of physical activity is needed to guide clinicians in the promotion of physical activity.     

Glycemic control from 1988 to 2000 among U.S. adults diagnosed with type 2 diabetes: a preliminary report

OBJECTIVE: To describe the changes in demographics, antidiabetic treatment, and glycemic control among the prevalent U.S. adult diagnosed type 2 diabetes population between the National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and the initial release of NHANES 1999-2000. RESEARCH DESIGN AND METHODS: The study population was derived from NHANES III (n = 1,215) and NHANES 1999-2000 (n = 372) subjects who reported a diagnosis of type 2 diabetes with available data on diabetes medication and HbA(1c). Four therapeutic regimens were defined: diet only, insulin only, oral antidiabetic drugs (OADs) only, or OADs plus insulin. Multiple logistic regression was used to examine changes in antidiabetic regimens and glycemic control rates over time, adjusted for demographic and clinical risk factors. The outcome measure for glycemic control was HbA(1c). Glycemic control rates were defined as the proportion of type 2 diabetic patients with HbA(1c) level <7%. RESULTS: Dietary treatment in individuals with diabetes decreased as the sole therapy from 27.4 to 20.2% between the surveys. Insulin use also decreased from 24.2 to 16.4%, while those on OADs only increased from 45.4 to 52.5%. Combination of OADs and insulin increased from 3.1 to 11.0%. Glycemic control rates declined from 44.5% in NHANES III (1988-1994) to 35.8% in NHANES 1999-2000. CONCLUSIONS: Treatment regimens among U.S. adults diagnosed with type 2 diabetes have changed substantially over the past 10 years. However, a decrease in glycemic control rates was also observed during this time period. This trend may contribute to increased rates of macrovascular and microvascular diabetic complications, which may impact health care costs. Our data support the public health message of implementation of early, aggressive management of diabetes.     

Diabetes-related morbidity and mortality in a national sample of U.S. elders

OBJECTIVE: Although the number of elders with diabetes has increased dramatically, there are few data on rates of mortality and serious complications in older populations with diabetes. To determine such rates, we conducted a population-based, nonconcurrent cohort study using claims data from the 1994-1996 Medicare 5% Standard Analytical File. RESEARCH DESIGN AND METHODS: Codes from the ICD-9 were used to identify diabetes and the following complications: amputation, lower extremity infection, gangrene, blindness, acute myocardial infarction, ischemic heart disease, stroke, and metabolic disorders. Using these codes, we assembled a cohort of 148,562 Medicare Part A and B beneficiaries who were > or = 65 years of age, who were alive on 1 January 1995, who were not in managed care in 1994, and who had a diabetes-related claim in 1994. Age-specific rates of death and complications were then calculated. RESULTS: During 24 months of follow-up, 22,044 (14.8%) elders with diabetes died. Death rates in men and women increased significantly with age. Compared with their counterparts in the general U.S. population, elders with diabetes suffered excess mortality at every age group, corresponding to an overall standardized mortality ratio of 1.41 (95% CI 1.39,1.43). The incidence of ischemic heart disease and stroke was 181.5 and 126.2 per 1,000 person-years, respectively, which was higher than the incidence of all other diabetes-related complications. CONCLUSIONS: In every age group, elders with diabetes have significantly higher all-cause mortality rates than the general population. Medicare data may be useful in monitoring trends in diabetes-related morbidity and total mortality in U.S. elders with diabetes.     

Relationships between hyperglycemia and cognitive performance among adults with type 1 and type 2 diabetes

OBJECTIVE: Hyperglycemia is a common event among patients with type 1 and type 2 diabetes. While the cognitive-motor slowing associated with hypoglycemia is well documented, the acute effects of hyperglycemia have not been studied extensively, despite patients' reports of negative effects. This study prospectively and objectively assessed the effects of hyperglycemia on cognitive-motor functioning in subjects' natural environment. RESEARCH DESIGN AND METHODS: Study 1 investigated 105 adults with type 1 diabetes (mean age 37 years and mean duration of diabetes 20 years), study 2 investigated 36 adults with type 2 diabetes (mean age 50 years and mean duration of diabetes 10 years), and study 3 investigated 91 adults with type 1 diabetes (mean age 39 years and mean duration of diabetes 20 years). Subjects used a hand-held computer for 70 trials over 4 weeks, which required them to complete various cognitive-motor tasks and then measure and enter their current blood glucose reading. RESULTS: Hyperglycemia (blood glucose >15 mmol/l) was associated with slowing of all cognitive performance tests (P < 0.02) and an increased number of mental subtraction errors for both type 1 and type 2 diabetic subjects. The effects of hyperglycemia were highly individualized, impacting approximately 50% of the subjects. CONCLUSIONS: Acute hyperglycemia is not a benign event for many individuals with diabetes, but it is associated with mild cognitive dysfunction.     

Pharmacological treatment of hyperglycemia in type 2 diabetes

Diabetes mellitus is a major public health problem, affecting about 10% of the population. Pharmacotherapy aims to protect against microvascular complications, including blindness, end-stage kidney disease, and amputations. Landmark clinical trials have demonstrated that intensive glycemic control slows progression of microvascular complications (retinopathy, nephropathy, and neuropathy). Long-term follow-up has demonstrated that intensive glycemic control also decreases risk of macrovascular disease, albeit rigorous evidence of macrovascular benefit did not emerge for over a decade. The US FDA’s recent requirement for dedicated cardiovascular outcome trials ushered in a golden age for understanding the clinical profiles of new type 2 diabetes drugs. Some clinical trials with sodium-glucose cotransporter-2 (SGLT2) inhibitors and glucagon-like peptide 1 (GLP1) receptor agonists reported data demonstrating cardiovascular benefit (decreased risk of major adverse cardiovascular events and hospitalization for heart failure) and slower progression of diabetic kidney disease. This Review discusses current guidelines for use of the 12 classes of drugs approved to promote glycemic control in patients with type 2 diabetes. The Review also anticipates future developments with potential to improve the standard of care: availability of generic dipeptidylpeptidase-4 (DPP4) inhibitors and SGLT2 inhibitors; precision medicine to identify the best drugs for individual patients; and new therapies to protect against chronic complications of diabetes.

Diabetes mellitus is a major public health problem, affecting about 10% of the population (1). Chronic complications of diabetes cause enormous human suffering, including blindness, kidney failure, amputations, myocardial infarction, and stroke. Inspired by the desire to develop better therapies, many researchers have investigated the pathophysiology of type 2 diabetes (T2D). While type 1 diabetes (T1D) is caused by autoimmune destruction of insulin-secreting β cells of the pancreas, T2D is often associated with obesity and is characterized by both impaired insulin secretion and insulin resistance (2). T2D is a progressive disease. Insulin resistance manifests early in the natural history prior to occurrence of overt hyperglycemia. So long as pancreatic β cells secrete sufficient insulin to compensate for insulin resistance, glucose levels are maintained at relatively normal levels (3). Overt diabetes occurs when β cells no longer secrete sufficient insulin to maintain normoglycemia. Fasting hyperglycemia is driven by increased hepatic glucose production due to relatively low insulin levels combined with hepatic insulin resistance. Severity of metabolic defects increases over time, primarily because of increasingly severe impairment in insulin secretion.This Review will discuss the state of the art in pharmacotherapy of T2D. Treatment aims to prevent or delay occurrence of microvascular and macrovascular complications — the main causes of morbidity and mortality in T2D. We focus specifically on hemoglobin A_1c–lowering (HbA1c-lowering) drugs, although antihypertensives, lipid-lowering drugs, optimal nutrition, and physical exercise also contribute to a holistic approach to treatment.     

Lifetime costs of complications resulting from type 2 diabetes in the U.S

OBJECTIVE:To model the lifetime costs associated with complications of type 2 diabetes. RESEARCH DESIGN AND METHODS: A cohort of 10,000 patients with diabetes was simulated using a model based on existing epidemiological studies. Complication rates were estimated for various stages of macrovascular disease, nephropathy, retinopathy, neuropathy, and hypoglycemia. At the beginning of the simulation, patients were assumed to have been treated for 5 years and have a mean HbA1c of 8.4. From the U.K. Prospective Diabetes Study, it was estimated that on current therapies, the HbA1c would drift upward on average 0.15% per year. Direct medical costs of managing each complication were estimated (in 2000 U.S. dollars) from all-payor databases, surveys, and literature. RESULTS: Macrovascular disease was estimated to be the largest cost component, accounting for 85% of cumulative costs of complications over the first 5 years. The costs of complications were estimated to be $47,240 per patient over 30 years, on average. The management of macrovascular disease is estimated to be the largest cost component, accounting for 52% of the costs; nephropathy accounts for 21%, neuropathy accounts for 17%, and retinopathy accounts for 10% of the costs of complications. CONCLUSIONS: The complications of diabetes account for substantial costs, with management of macrovascular disease being the largest and earliest. If improving glycemic control prevents complications, it will reduce these costs.     

Dental and other health care visits among U.S. adults with diabetes

OBJECTIVE: This study compared yearly dental visits of diabetic adults with those of nondiabetic adults. For adults with diabetes, we compared the frequency of past-year dental visits with past-year visits for diabetes care, dilated eye examinations, and foot examinations. RESEARCH DESIGN AND METHODS: We conducted a cross-sectional study using a sample of 105,718 dentate individuals aged > or =25 years, including 4,605 individuals with diabetes who participated in the 1995-1998 Behavioral Risk Factor Surveillance System in 38 states. RESULTS: Dentate adults (i.e., those with at least some natural teeth) with diabetes were less likely than those without diabetes to have seen a dentist within the preceding 12 months (65.8 vs. 73.1%, P = 0.0000). Adults with diabetes were less likely to have seen a dentist than to have seen a health care provider for diabetes care (86.3%); the percentage who saw a dentist was comparable with the percentage who had their feet examined (67.7%) or had a dilated eye examination (62.3%). The disparity in dental visits among racial or ethnic groups and among socioeconomic groups was greater than that for any other type of health care visit for subjects with diabetes. CONCLUSIONS: Promotion of oral health among diabetic patients may be necessary, particularly in Hispanic and African-American communities. Information on oral health complications should be included in clinical training programs. Oral and diabetes control programs in state health departments should collaborate to promote preventive dental services, and the oral examination should be listed as a component of continuous care in the American Diabetes Association's standards of medical care for diabetic patients.     

Physical activity in U.S. adults with diabetes and at risk for developing diabetes, 2003

OBJECTIVE: Given the risk of obesity and diabetes in the U.S., and clear benefit of exercise in disease prevention and management, this study aimed to determine the prevalence of physical activity among adults with and at risk for diabetes. RESEARCH DESIGN AND METHODS: The Medical Expenditure Panel Survey is a nationally representative survey of the U.S. population. In the 2003 survey, 23,283 adults responded when asked about whether they were physically active (moderate or vigorous activity, > or =30 min, three times per week). Information on sociodemographic characteristics and health conditions were self-reported. Additional type 2 diabetes risk factors examined were age > or =45 years, non-Caucasian ethnicity, BMI > or =25 kg/m(2), hypertension, and cardiovascular disease. RESULTS: A total of 39% of adults with diabetes were physically active versus 58% of adults without diabetes. The proportion of active adults without diabetes declined as the number of risk factors increased until dropping to similar rates as people with diabetes. After adjustment for sociodemographic and clinical factors, the strongest correlates of being physically active were income level, limitations in physical function, depression, and severe obesity (BMI > or =40 kg/m(2)). Several traditional predictors of activity (sex, education level, and having received past advice from a health professional to exercise more) were not evident among respondents with diabetes. CONCLUSIONS: The majority of patients with diabetes or at highest risk for developing type 2 diabetes do not engage in regular physical activity, with a rate significantly below national norms. There is a great need for efforts to target interventions to increase physical activity in these individuals.     

Toenail selenium and incidence of type 2 diabetes in U.S. men and women

OBJECTIVE

Compelling biological pathways suggest that selenium (Se) may lower onset of type 2 diabetes mellitus (T2DM), but very few studies have evaluated this relationship, with mixed results. We examined the association between toenail Se and incidence of T2DM.

RESEARCH DESIGN AND METHODS

We performed prospective analyses in two separate U.S. cohorts, including 3,630 women and 3,535 men, who were free of prevalent T2DM and heart disease at baseline in 1982–1983 and 1986–1987, respectively. Toenail Se concentration was quantified using neutron activation analysis, and diabetes cases were identified by biennial questionnaires and confirmed by a detailed supplementary questionnaire. Hazard ratios of incident T2DM according to Se levels were calculated using Cox proportional hazards.

RESULTS

During 142,550 person-years of follow-up through 2008, 780 cases of incident T2DM occurred. After multivariable adjustment, the risk of T2DM was lower across increasing quintiles of Se, with pooled relative risks across the two cohorts of 1.0 (reference), 0.91 (95% CI 0.73–1.14), 0.78 (0.62–0.99), 0.72 (0.57–0.91), and 0.76 (0.60–0.97), respectively (P for trend = 0.01). Results were similar excluding the few individuals (4%) who used Se supplements. In semiparametric analyses, the inverse relationship between Se levels and T2DM risk appeared to be linear.

CONCLUSIONS

At dietary levels of intake, individuals with higher toenail Se levels are at lower risk for T2DM. Further research is required to determine whether varying results in this study versus prior trials relate to differences in dose, source, statistical power, residual confounding factors, or underlying population risk.Accumulating evidence indicates that excess oxidative stress is a risk factor for insulin resistance, β-cell dysfunction, impaired glucose tolerance, and type 2 diabetes mellitus (T2DM) (1–3). Selenium (Se), an essential trace nutrient, is a critical component of numerous selenoproteins involved in antioxidant defense systems, such as glutathione peroxidase, which actively protect against damage from free radicals and reactive oxygen species (4,5). Increased free radical levels impair glucose-stimulated insulin secretion, decrease gene expression of key β-cell genes, and induce cell death (2,6–8).Investigations into the effects of habitual Se consumption on chronic disease in humans have been limited by challenges in accurately assessing Se intake from dietary questionnaires, due to errors in recall, geographic variation in Se exposures, and wide variations in Se content of otherwise similar foods. In this setting, measurements of toenail Se concentrations provide a valid and objective biomarker of long-term (∼1 year) Se consumption (9). However, to our knowledge, no prior investigations have followed large numbers of individuals with both biomarker measures and sufficiently long durations of follow-up to assess development of T2DM.Although compelling biological evidence suggests that Se might reduce the onset of T2DM, results of prior cross-sectional studies have been conflicting. One prior study observed an inverse association between toenail Se and prevalent T2DM (10), whereas two other studies using data from the U.S. National Health and Nutrition Examination Survey showed nonlinear positive associations between serum Se and prevalence of T2DM (11,12). Such cross-sectional studies are limited by an inability to assess temporal relationships, in that diabetes status could alter Se levels. In two randomized clinical trials (13,14), Se supplementation did not reduce the incidence of T2DM. However, these studies evaluated the effects of relatively high Se dosages in specific high–cancer risk populations rather than the effects of dietary doses derived from foods in more general populations. To our knowledge, no study has prospectively evaluated the relationship between habitual dietary Se consumption, as assessed through a valid Se biomarker, and the incidence of T2DM. Therefore, we prospectively evaluated whether Se consumption, as assessed by an objectively measured toenail-Se biomarker, was associated with lower incidence of T2DM in women and men in two separate U.S. cohort studies: the Nurses’ Health Study (NHS) and the Health Professionals Follow-Up Study (HPFS).     

Detecting type 2 diabetes by a single post-challenge blood sample.

In the recent American Diabetes Association (ADA)/WHO recommendations, the oral glucose tolerance test (OGTT) was replaced by the measurement of a single fasting glucose concentration with a decision limit for the detection of type 2 diabetes mellitus (DM) reduced. This proposal, however, misses all cases of isolated post-prandial hyperglycaemia. Therefore, a study was undertaken to develop a post-challenge, one-sample mode of diagnosis. OGTT was performed in 240 high-risk subjects who were suspected to suffer from type 2 DM. Glucose concentrations were determined at 30 min intervals in the capillary blood, venous blood and plasma, and insulin was determined in venous plasma only. The test results were classified in non-disease and disease group according to the decision limits recommended by ADA/WHO. Furthermore, the early insulin response and an insulin sensitivity index were used to determine new cut-off values. These were identified as the concentrations demonstrating the highest diagnostic efficiency and were lower than the WHO limits. The 2 h post-load plasma concentration led to higher efficiency at a cut-off value of 9.0 mmol/l glucose (162 mg/dl) compared to concentrations of samples taken in the fasting state, at an earlier time of the OGTT, or in venous and capillary blood. Under this condition, 72 diabetic patients (35%) were detected in the study group (n = 207), whereas only 36 (17%) were found with one sample in the fasting state and 53 (26%) with two samples using the ADA/WHO criteria. Therefore, a single venous plasma sample taken after 2 h post-glucose challenge appeared to be most efficient for the early detection of DM.     

Weighing in on type 2 diabetes in the military: characteristics of U.S. military personnel at entry who develop type 2 diabetes.

OBJECTIVES: Current incidence trends in type 2 diabetes portend a significant public health burden and have largely been attributed to similar trends in overweight and physical inactivity. Medical surveillance of the U.S. military indicates that the incidence of all types of diabetes is similar to that in the civilian population (1.9 vs. 1.6 cases per 1,000 person-years) despite weight and fitness standards. Differences in the common determinants of diabetes have not been studied in the military population, which may provide novel clues to the increasing incidence of diabetes in the U.S. RESEARCH DESIGN AND METHODS: A case-control study, 4-to-1 matched for age, sex, entry date, time in service, and service component (e.g., Army, Navy), was used to describe the association of race/ethnicity, socioeconomic status, and BMI and blood pressure at entry into military service with the subsequent development of type 2 diabetes. RESULTS: Increased BMI (adjusted odds ratio, 3.0 for the > or =30 kg/m(2) vs. < or =20 kg/m(2) categories and 2.0 for the 25.0-29.9 kg/m(2) category, compared with the reference category), African-American (adjusted odds ratio, 2.0) and Hispanic origin (adjusted odds ratio, 1.6) compared with white race and rank (adjusted odds ratio for junior enlisted versus officers, 4.1) were all associated with type 2 diabetes. CONCLUSIONS: Individuals with type 2 diabetes in the U.S. military have risk factors similar to the general U.S. population. Because diabetes is a preventable disease, it is of concern that it is occurring in this population of younger and presumably more fit individuals. This has significant implications for the prevention of diabetes in both military and civilian populations.     

Influence of familial risk on diabetes risk-reducing behaviors among U.S. adults without diabetes

OBJECTIVE

To test the association of family history of diabetes with the adoption of diabetes risk–reducing behaviors and whether this association is strengthened by physician advice or commonly known factors associated with diabetes risk.

RESEARCH DESIGN AND METHODS

We used cross-sectional data from the 2005–2008 National Health and Nutrition Examination Survey (NHANES) to examine the effects of family history of diabetes on the adoption of selected risk-reducing behaviors in 8,598 adults (aged ≥20 years) without diabetes. We used multiple logistic regression to model three risk reduction behaviors (controlling or losing weight, increasing physical activity, and reducing the amount of dietary fat or calories) with family history of diabetes.

RESULTS

Overall, 36.2% of U.S. adults without diabetes had a family history of diabetes. Among them, ~39.8% reported receiving advice from a physician during the past year regarding any of the three selected behaviors compared with 29.2% of participants with no family history (P < 0.01). In univariate analysis, adults with a family history of diabetes were more likely to perform these risk-reducing behaviors compared with adults without a family history. Physician advice was strongly associated with each of the behavioral changes (P < 0.01), and this did not differ by family history of diabetes.

CONCLUSIONS

Familial risk for diabetes and physician advice both independently influence the adoption of diabetes risk–reducing behaviors. However, fewer than half of participants with familial risk reported receiving physician advice for adopting these behaviors.The Centers for Disease Control and Prevention (CDC) recently reported that 25.8 million people in the U.S. (8.3% of the population) have diabetes (1). A total of 1.9 million new cases of diabetes were diagnosed in people aged ≥20 years in 2010 in the U.S., and 25.6 million (11.3%) people in this age-group have diabetes. Worldwide, it is estimated that 280 million people had diabetes in 2010—a number that is projected to increase to 430 million by 2030 (2). Studies have reported strong and consistent evidence that lifestyle factors might prevent or delay type 2 diabetes among people at high risk, including those with a family history of the disease (3,4). In 2002, the World Health Report (5) identified risk-reducing behaviors (such as controlling or losing weight, increasing physical activity, and reducing fat or calories) as important lifestyle risk factors for a number of chronic diseases, including diabetes, cardiovascular disease, and cancer.Many variables, including genetic, environmental, medical, and socioeconomic factors, influence the development of diabetes (6). The association of family history of diabetes with risk for the disease has been well documented (7). Although a 2009 National Institutes of Health State of the Science conference concluded that there was insufficient evidence to support the routine use of family history as a screening tool for risk of common complex conditions in primary care (8), an individual patient’s family history remains a critical element in risk assessment for many chronic conditions, including diabetes (9). While accurate and complete family history information needs to be collected to identify high-risk individuals, substantial barriers exist to obtaining this information in primary care practice, though clinicians are trained to do so. These barriers include lack of time to collect the information, lack of proper training to interpret the information, and lack of reimbursement (10).Evidence also supports the effectiveness of physician advice on lifestyle modifications to prevent or delay the risk of chronic diseases (11). A recent study on diabetes risk reduction behaviors found that the proportion of adults with prediabetes who reported performing risk reduction behaviors was higher among those who received physician advice compared with those who did not receive such advice (12).In light of the evidence summarized above, we used data from the 2005–2008 National Health and Nutrition Examination Survey (NHANES), a large population-based and nationally representative survey of the U.S., to test the hypotheses that a family history of diabetes is associated with greater adoption of diabetes risk–reducing behaviors and that the association is strengthened by the receipt of physician advice regarding these behaviors, in addition to other commonly known factors associated with diabetes risk.     

Carbohydrate-induced memory impairment in adults with type 2 diabetes

OBJECTIVE: Memory impairment is observed in adults with type 2 diabetes. The focus of this study was to determine whether acute carbohydrate consumption contributes to or exacerbates memory dysfunction. RESEARCH DESIGN AND METHODS: The impact of consuming 50 g of rapidly absorbed carbohydrate (one half bagel and white grape juice) at breakfast was examined in 19 adults with type 2 diabetes. Subjects (mean age 63 +/- 9 years, mean BMI 26.1 +/- 4.5 kg/m(2)) were tested, under fed and fasted conditions, on verbal declarative memory using both word list and paragraph recall tests (immediate and delayed [7-min] recall), Trails Test Part B as a measure of general brain function, and mood (subjectively monitoring global vigor and affect). RESULTS: Under baseline (fasting) conditions, elevated blood HbA(1c) was negatively associated with immediate and delayed paragraph recall performance (R(2) = 0.30; P = 0.024) and higher fasting blood glucose trended toward poorer word list recall (R(2) = 0.09; P = 0.102). Carbohydrate ingestion influenced measures of delayed, but not immediate, recall in a time-dependent fashion (time x food) (word list, P = 0.046; paragraph, P = 0.044) such that delayed recall was improved at 15 min postingestion but was impaired at 30 min. Neither Trails Test scores (P = 0.17) nor mood (affect, P = 0.68 and vigor, P = 0.45) were influenced by food ingestion. CONCLUSIONS: In adults with type 2 diabetes, poorer glycemic control is associated with lower performance on tests of declarative memory. Acute ingestion of high glycemic index carbohydrate foods further contributes to the underlying memory impairment.     

Predictors of RNs' intent to work and work decisions 1 year later in a U.S. national sample

Background

Many studies have examined predictors of nurses’ intention to work in their job, including desire to quit. Intent has been a good predictor of actual turnover. Few longitudinal studies exist that consider regional variables.

Objectives

To extend the conceptual framework of turnover research to the whole nursing workforce and determine: (1) how do demographics, region (metropolitan statistical area: MSA), movement opportunities, and work setting variables affect registered nurses’ (RNs) intent to work and desire to quit; and (2) how do demographics, MSA variables, movement opportunities, and work setting variables affect RNs’ work behavior at time 2?

Design

Panel study using Dillman's design method.

Settings and participants

Randomly selected national cluster sample from 40 urban geographic regions (MSAs) in 29 states of the United States.

Methods

Four thousand surveys were sent. There were 1907 female RNs under 65 (48% response rate) from year 1 of which 1348 responded at year 2 (70% response rate).

Results

The first analyses used desire to quit (explained 65% of the variance) and intent to work from year 1 as dependent variables. Satisfaction and organizational commitment were significant negative predictors of desire to quit. In the logistic regression on intent to work, the work motivation and work-family conflict were positive and significant as well as wages (negative) and three benefit variables. In year 2, the dependent variable was working or not and if working, full-time or not. For this bivariate probit regression no attitudes influenced the work/not work decision, but MSA level variables, wages (positive) and benefits (positive) did. Organizational commitment and higher workload increased the probability of working FT.

Conclusions

Regional differences across markets need to be controlled and their influence investigated. In addition, attitudes as well as wages and benefits were important in certain decisions: these factors are clearly under the influence of employers.