David C. Ziemer

Patient adherence improves glycemic control

Purpose The purpose of this study was to assess the influence of appointment keeping and medication adherence on HbA1c. Methods A retrospective evaluation was performed in 1560 patients with type 2 diabetes who presented for a new visit to the Grady Diabetes Clinic between 1991 and 2001 and returned for a follow-up visit and HbA1c after 1 year of care. Appointment keeping was assessed by the number of scheduled intervening visits that were kept, and medication adherence was assessed by the percentage of visits in which self-reported diabetes medication use was as recommended at the preceding visit. Results The patients had an average age of 55 years, body mass index (BMI) of 32 kg/m2, diabetes duration of 4.6 years, and baseline HbA1c of 9.1%. Ninety percent were African American, and 63% were female. Those who kept more intervening appointments had lower HbA1c levels after 12 months of care (7.6% with 6-7 intervening visits vs 9.7% with 0 intervening visits). Better medication adherence was also associated with lower HbA1c levels after 12 months of care (7.8% with 76%-100% adherence). After adjusting for age, gender, race, BMI, diabetes duration, and diabetes therapy in multivariate linear regression analysis, the benefits of appointment keeping and medication adherence remained significant and contributed independently; the HbA1c was 0.12% lower for every additional intervening appointment that was kept (P= .0001) and 0.34% lower for each quartile of better medication adherence (P= .0009). Conclusion Keeping more appointments and taking diabetes medications as directed were associated with substantial improvements in HbA1c. Efforts to enhance glycemic outcomes should include emphasis on these simple but critically important aspects of patient adherence.

Glucose-Independent, Black–White Differences in Hemoglobin A1c Levels: A Cross-sectional Analysis of 2 Studies

BACKGROUND A previous study of participants with prediabetes found that hemoglobin A(1c) (HbA(1c)) levels differed between black and white participants with no differences in glucose concentration. OBJECTIVE To determine whether black-white differences in HbA(1c) level are present in other populations and across the full spectrum of glycemia. DESIGN Cross-sectional, retrospective. SETTING Outpatient. PARTICIPANTS 1581 non-Hispanic black and white participants between 18 and 87 years of age without known diabetes in the SIGT (Screening for Impaired Glucose Tolerance) study and 1967 non-Hispanic black and white participants older than 40 years without known diabetes in the NHANES III (Third National Health and Nutrition Examination Survey). MEASUREMENTS HbA(1c) levels, anthropometry, and plasma glucose levels during oral glucose tolerance testing. RESULTS Hemoglobin A(1c) levels were higher in black than in white participants with normal glucose tolerance (0.13 percentage point [P < 0.001] in the SIGT sample and 0.21 percentage point [P < 0.001] in the NHANES III sample), prediabetes (0.26 percentage point [P < 0.001] and 0.30 percentage point [P < 0.001], respectively), or diabetes (0.47 percentage point [P < 0.020] and 0.47 percentage point [P < 0.013], respectively) after adjustment for plasma glucose levels and other characteristics known to correlate with HbA(1c) levels. LIMITATION The mechanism for the differences is unknown. CONCLUSION Black persons have higher HbA(1c) levels than white persons across the full spectrum of glycemia, and the differences increase as glucose intolerance worsens. These findings could limit the use of HbA(1c) to screen for glucose intolerance, indicate the risk for complications, measure quality of care, and evaluate disparities in health.

Clinical Inertia Contributes to Poor Diabetes Control in a Primary Care Setting

Purpose The purpose of this study was to determine whether “clinical inertia”—inadequate intensification of therapy by the provider—could contribute to high A1C levels in patients with type 2 diabetes managed in a primary care site. Methods In a prospective observational study, management was compared in the Medical Clinic, a primary care site supervised by general internal medicine faculty, and the Diabetes Clinic, a specialty site supervised by endocrinologists. These municipal hospital clinics serve a common population that is largely African American, poor, and uninsured. Results Four hundred thirty-eight African American patients in the Medical Clinic and 2157 in the Diabetes Clinic were similar in average age, diabetes duration, body mass index, and gender, but A1C averaged 8.6% in the Medical Clinic versus 7.7% in the Diabetes Clinic (P < .0001). Use of pharmacotherapy was less intensive in the Medical Clinic (less use of insulin), and when patients had elevated glucose levels during clinic visits, therapy was less than half as likely to be advanced in the Medical Clinic compared to the Diabetes Clinic (P < .0001). Intensification rates were lower in the Medical Clinic regardless of type of therapy (P < .0001), and intensification of therapy was independently associated with improvement in A1C (P < .001). Conclusions Medical Clinic patients had worse glycemic control, were less likely to be treated with insulin, and were less likely to have their therapy intensified if glucose levels were elevated. To improve diabetes management and glycemic control nationwide, physicians in training and generalists must learn to overcome clinical inertia, to intensify therapy when appropriate, and to use insulin when clinically indicated.

Screening for Diabetes and Pre-Diabetes With Proposed A1C-Based Diagnostic Criteria

OBJECTIVE An International Expert Committee (IEC) and the American Diabetes Association (ADA) proposed diagnostic criteria for diabetes and pre-diabetes based on A1C levels. We hypothesized that screening for diabetes and pre-diabetes with A1C measurements would differ from using oral glucose tolerance tests (OGTT). RESEARCH DESIGN AND METHODS We compared pre-diabetes, dysglycemia (diabetes or pre-diabetes), and diabetes identified by the proposed criteria (A1C ≥6.5% for diabetes and 6.0–6.4% [IEC] or 5.7–6.4% [ADA] for high risk/pre-diabetes) with standard OGTT diagnoses in three datasets. Non-Hispanic white or black adults without known diabetes who had A1C and 75-g OGTT measurements were included from the prospective Screening for Impaired Glucose Tolerance study (n = 1,581), and from the National Health and Nutrition Examination Survey (NHANES) III (n = 2014), and NHANES 2005–2006 (n = 1,111). RESULTS OGTTs revealed pre-diabetes in 35.8% and diabetes in 5.2% of combined study subjects. A1C provided receiver operating characteristic (ROC) curve areas for diabetes of 0.79–0.83, but ROC curve areas were ≤0.70 for dysglycemia or pre-diabetes. The proposed criteria missed 70% of individuals with diabetes, 71–84% with dysglycemia, and 82–94% with pre-diabetes. Compared with the IEC criteria, the ADA criteria for pre-diabetes resulted in fewer false-negative and more false-positive result. There were also racial differences, with false-positive results being more common in black subjects and false-negative results being more common in white subjects. With use of NHANES 2005–2006 data, ∼5.9 million non-Hispanic U.S. adults with unrecognized diabetes and 43–52 million with pre-diabetes would be missed by screening with A1C. CONCLUSIONS The proposed A1C diagnostic criteria are insensitive and racially discrepant for screening, missing most Americans with undiagnosed diabetes and pre-diabetes.

Patient Activation Is Associated With Healthy Behaviors and Ease in Managing Diabetes in an Indigent Population

Purpose The purpose of this study is to assess the validity of the patient activation construct as measured by the Patient Activation Measure (PAM) survey by correlating PAM scores with diabetes self-management behaviors, attitudes, and knowledge in a predominantly minority and uninsured population. Methods A convenience sample of patients presenting to an urban public hospital diabetes clinic was surveyed and contacted by phone 6 months later. The survey included questions about activation, health behaviors, and health care utilization. Results A total of 287 patients agreed to participate. Most were African American, female, and uninsured. Most respondents (62.2%) scored in the highest category of activation according to the PAM. Activated patients were more likely to perform feet checks, receive eye examinations, and exercise regularly. Activation was consistently associated with less reported difficulty in managing diabetes care but not with A1C knowledge. PAM scores at the initial interview were highly correlated with scores at 6-month follow-up. Activation level did not predict differences in health care utilization during the 6 months following the survey. Conclusions Higher scores on the PAM were associated with higher rates of self-care behaviors and ease in managing diabetes; however, the indigent urban population reported higher activation scores than found in previous studies. The relationship between activation and outcomes needs to be explored further prior to expanding use of this measure in this patient population.

Perception of Barriers to Self-care Management Among Diabetic Patients

Purpose The purpose of this study was to explore individual, educational, and system barriers that limit low-income diabetes patients’ ability to achieve optimal diabetes self-management. Methods Economically disadvantaged patients with diabetes who used the Diabetes Clinic of Grady Health System in Atlanta, Georgia, participated in 3 focus group discussions. Results The discussions were held with mostly African Americans (n = 35) to explore barriers to achieving optimal diabetes self-management. Most participants were not married, approximately one-third had less than high school level reading skills, and 40% were not currently working. In terms of individual barriers, the emotional toll from the diagnosis of and lifestyle changes to treat diabetes was a recurrent theme, and included stress, frustration, social isolation, interpersonal conflicts, depression, and fear. Denial was often mentioned as the key factor that inhibited adherence to a healthy mode of living. The educational barriers were failure to recognize the risks and consequences of an asymptomatic condition. Many participants did not understand A1C. Finally, several system barriers were identified. The participants identified needed services, including follow-up and refresher courses, support group discussions, nutrition and medication education, availability of different education modalities, and expanded clinic hours. Conclusions The focus group discussions identified both barriers to diabetes management and opportunities for improving care for underserved patients with diabetes. The results are useful to improve the delivery of care and to develop quantitative studies to explore particular areas of interest. Based on these results, the current system needs to provide more support and education to patients with diabetes.

Diabetes in Urban African-Americans: II. High prevalence of microalbuminuria and nephropathy in African-Americans with diabetes

OBJECTIVE African-Americans with diabetes have an increased risk of endstage renal disease, but underlying mechanisms are poorly understood. We undertook this study to evaluate prevalence and risk factors for renal disease in an African-American population with diabetes. RESEARCH DESIGN AND METHODS We measured urine albumin excretion in 578 consecutive patients presenting for the first time to the Grady Memorial Hospital Diabetes Unit in Atlanta, GA. The unit serves an urban population that is predominantly African-American; 85% of patients have non-insulin-dependent diabetes mellitus (NIDDM). Subjects provided 24-h and/or ∼ 3-h urine collections for measurement of albumin and creatinine. RESULTS Correlation of the albumin/creatinine ratio (μg/mg) with the 24-h albumin excretion rate was 0.89 (P < 0.001, n = 123). Although the median duration of diabetes was only 1 year, among all subjects, the estimated prevalence of microalbuminuria (30–300 mg albumin/24 h) was 25% and that of nephropathy (> 300 mg albumin/24 h) was 11%. Among African-Americans with NIDDM (n = 466), the estimated prevalence of microalbuminuria was 24% and that of nephropathy was 12% prevalence remained high (25 and 5%, respectively) among 219 patients with < 1 year known duration of diabetes. Metabolic control was not associated with disease. However, among all subjects with NIDDM, the odds ratio for nephropathy among subjects with disease duration > 5 years compared with those with disease duration < 1 year was 4.65 (95% confidence interval [CI] 2.24–9.79), and the odds ratio for nephropathy among subjects with hypertension compared with those without hypertension was 2.64 (CI 1.42–4.93). Odds ratios were comparable among African-Americans with NIDDM. Trends were similar but less significant for subjects with microalbuminuria. CONCLUSIONS Albuminuria can be identified reliably and conveniently by the albumin/creatinine ratio in brief urine collections. In our patients, clinically significant albuminuria occurred in 36% of persons at first presentation. Since increased risk was associated with hypertension and control of hypertension can slow progression of renal disease, screening for albuminuria and treatment of hypertension should be aggressive in urban populations of African-Americans with diabetes.

Diabetes in Urban African-Americans. IX. Provider Adherence to Management Protocols

OBJECTIVE Staged diabetes management should permit glycemic goals to be attained in a timely manner, but the success of such an approach requires conformity by health care providers. To test performance, we analyzed the adherence of practitioners to a protocol for staged management of NIDDM patients. RESEARCH DESIGN AND METHODS Records of patients treated at the Grady Memorial Hospital Diabetes Clinic were reviewed retrospectively over a 3-year period. For each patient, intensification of therapy was indicated if fasting plasma glucose was > 7.8 mmol/l and a prior HbA1c was > 7.0%. Protocols dictated a progression from dietary therapy alone to increasing dosages of sulfonylureas to increasing dosages of insulin. Patients were seen at bimonthly intervals. RESULTS During the 3-year period, 1,051 patient visits met protocol criteria for intensification. Adherence to the protocol improved significantly in the 3rd year compared with the first 2 years (30, 31, and 47% adherence in the 1st, 2nd, and 3rd years, respectively). Patients treated with diet alone were significantly less likely to have their therapy intensified than patients on sulfonylureas or insulin (intensification rates 25, 41, and 47%, respectively). In the management of patients treated with diet alone, practitioners were reluctant to intensify therapy at early visits, but were more likely to do so later, 19% of patients beyond goal range at the 2-month visit were started on pharmacological therapy vs. 28% at the 4-month visit, and 39% at the 6-month visit (P < 0.01). In contrast, there was no significant difference in the frequency of therapy intensification between early and late visits for patients on sulfonylureas or insulin. Practitioners appeared to base the decision to intensify on the fasting plasma glucose level more than on the most recent HbA1c. Age did not appear to be a significant factor in the decision to intensify. CONCLUSIONS Although staged management protocols constitute critical tools to achieve glycemic goals, the adherence of health care providers may be suboptimal. Special efforts may be needed to assure compliance.

Many Americans have pre-diabetes and should be considered for metformin therapy.

OBJECTIVE To determine the proportion of the American population who would merit metformin treatment, according to recent American Diabetes Association (ADA) consensus panel recommendations to prevent or delay the development of diabetes. RESEARCH DESIGN AND METHODS Risk factors were evaluated in 1,581 Screening for Impaired Glucose Tolerance (SIGT), 2,014 Third National Health and Nutrition Examination Survey (NHANES III), and 1,111 National Health and Nutrition Examination Survey 2005–2006 (NHANES 2005–2006) subjects, who were non-Hispanic white and black, without known diabetes. Criteria for consideration of metformin included the presence of both impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), with ≥1 additional diabetes risk factor: age <60 years, BMI ≥35 kg/m2, family history of diabetes, elevated triglycerides, reduced HDL cholesterol, hypertension, or A1C >6.0%. RESULTS Isolated IFG, isolated IGT, and IFG and IGT were found in 18.0, 7.2, and 8.2% of SIGT; 22.3, 6.4, and 9.4% of NHANES III; and 21.8, 5.0, and 9.0% of NHANES 2005–2006 subjects, respectively. In SIGT, NHANES III, and NHANES 2005–2006, criteria for metformin consideration were met in 99, 96, and 96% of those with IFG and IGT; 31, 29, and 28% of all those with IFG; and 53, 57, and 62% of all those with IGT (8.1, 9.1, and 8.7% of all subjects), respectively. CONCLUSIONS More than 96% of individuals with both IFG and IGT are likely to meet ADA consensus criteria for consideration of metformin. Because >28% of all those with IFG met the criteria, providers should perform oral glucose tolerance tests to find concomitant IGT in all patients with IFG. To the extent that our findings are representative of the U.S. population, ∼1 in 12 adults has a combination of pre-diabetes and risk factors that may justify consideration of metformin treatment for diabetes prevention.

Diabetes in urban african americans. III. Management of type II diabetes in a municipal hospital setting

OBJECTIVE Management of type II diabetes is difficult, particularly in urban populations with limited resources and access to care. To evaluate the effectiveness of structured care delivered by non-physician providers, patients were studied prospectively for 6 months in a municipal hospital diabetes clinic. DESIGN AND METHODS The population was approximately 90% African American and had median known diabetes duration of approximately 1 year, 54% had incomes below the Federal Poverty Guideline. Primary management was provided by nurse-practitioners and dietitians, and primary outcome measures were hemoglobin A1c (HbA1c), fasting plasma glucose, and changes in body weight. RESULTS Responses were analyzed in 325 new patients returning for visits at 2, 4, 6, and 12 months; metabolic profiles at presentation were similar to those of subjects who missed intervening visits. Lean patients largely continued on pharmacologic therapy and improved HbA1c from 9.4% to 7.4% at 2 months (P < 0.001), remained stable through 6 months, then rose to 7.9% at 1 year. Obese patients (71%) received dietary instruction. Weaning of pharmacologic therapy was attempted for the first 2 months, resulting in a decline of HbA1c from 9.6% to 8.0% (P < 0.001), with 70% treated with diet alone. In the obese, HbA1c continued to decrease through 6 months (7.7%). Thereafter, providers saw patients at their own discretion and intensified therapy as needed. Although by 1 year, HbA1c had risen to only 8.2%, some patients required reinstitution of pharmacologic therapy; 59% were on diet alone. While 52% lost 4 lb or more (mean 9.3) by 2 months, little additional weight was lost. Interestingly, glycemic control was improved both in those who lost > or = 8.5 lb in the first 2 months (HbA1c 9.6% to 8.1% at 12 months), and in those who gained weight (HbA1c 10.2% to 8.2%). In the obese patients using pharmacologic agents at presentation, 35% were able to discontinue oral agents or insulin by 1 year, with good glycemic control (HbA1c < 8%). For patients who were initially on diet alone, a fasting plasma glucose > 177 mg/dL predicted the need for pharmacologic therapy with 97% certainty. CONCLUSIONS In urban African American patients, nonpharmacologic management of type II diabetes substantially improves metabolic control; decreases in HbA1c are comparable in those who do and do not lose weight. Therapy managed by nonphysician providers can be an effective cornerstone of diabetes care in this socioeconomically disadvantaged population.