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Ronald P Stolk

Publications and source records attributed to Ronald P Stolk.

At least 19 recordsLinked to original sources

Common genetic variations in CCK, leptin, and leptin receptor genes are associated with specific human eating patterns.

Obesity has a heritable component; however, the heterogeneity of obesity complicates dissection of its genetic background. In this study, we therefore focused on eating patterns as specific traits within obesity. These traits have a heritable component; genes associated with a specific eating pattern have not yet been reported at the population level. In this study, we determined whether genetic variations in cholecystokinin (CCK) and leptin genes underlie specific eating patterns. We selected obese individuals showing extreme snacking behavior or use of excessive portion sizes from a large population-based sample (n = 17,357) from the Prospect-EPIC (European Prospective Study into Cancer and Nutrition) study. Using allele-specific PCRs, we tested several single nucleotide polymorphisms in the candidate genes and performed haplotype analysis. Obese carriers of common allelic variations in leptin or the leptin receptor gene had an increased risk to display extreme snacking behavior. In contrast, obese carriers of common allelic variations in CCK had an increased risk to eating increased meal sizes. In conclusion, we identified common allelic variants specifically associated with distinctly different eating patterns, namely extreme snacking behavior or excessive portion size.

Aged↗

Asymptomatic bacteriuria in women with diabetes mellitus: effect on renal function after 6 years of follow-up.

BACKGROUND: The long-term consequences of asymptomatic bacteriuria (ASB) on renal function in women with diabetes mellitus (DM) are unknown. METHODS: A prospective study was performed among women with type 1 or type 2 DM. Women with ASB (diagnosis based on findings from 1 urine culture specimen) were compared with women without ASB for differences in renal function development and incidence of hypertension. RESULTS: A total of 644 women were included in the study (296 with type 1 DM and 348 with type 2 DM; mean [SD] age, 51 [15] years) and followed up for a mean (SD) duration of 6.1 (1.9) years. The prevalence of ASB was 17%. In women with DM and ASB, the creatinine clearance decreased from 87 mL/min (1.45 mL/s) at baseline to 76 mL/min (1.27 mL/s) at study end point; in women with DM without ASB the creatinine clearance decreased from 97 to 88 mL/min (from 1.62 to 1.47 mL/s). In the multivariate analyses, adjusted for age, length of follow-up, duration of DM, and microalbuminuria at baseline, no association was found between ASB and the relative or the absolute decrease in creatinine clearance; the same results were shown also when women with DM type 1 and women with DM type 2 were analyzed separately. Women with ASB developed hypertension more often than women without ASB (54% vs 37%; P = .045), but there was no significant association in the multivariate analysis (odds ratio, 1.5; 95% confidence interval, 0.7-3.6). CONCLUSION: Women with DM (type 1 or type 2) with ASB do not have an increased risk for a faster decline in renal function or the development of hypertension after 6 years of follow-up.

Adolescent↗

Accident proneness, does it exist? A review and meta-analysis.

Accident related health problems have been suggested to cluster within persons. This phenomenon became known as accident proneness and has been a subject of many discussions. This study provides an overview of accident proneness. Therefore, 79 articles with empirical data on accident rates were identified from databases Embase, Medline, and Psychinfo. First, definitions of accidents varied highly, but most studies focused on accidents resulting in injuries requiring medical attention. Second, operationalisations of accident proneness varied highly. Studies categorised individuals into groups with ascending accident rates or made non-accident, accident, and repetitive accident groups. Third, studies examined accidents in specific contexts (traffic, work, and sports) or populations (children, students, and patients). Therefore, we concluded that no overall prevalence rate of accident proneness could be given due to the large variety in operationalisations. However, a meta-analysis of the distribution of accidents in the general population showed that the observed number of individuals with repeated accidents was higher than the number expected by chance. In conclusion, accident proneness exists, but its study is severely hampered by the variation in operationalisations of the concept. In an effort to reach professional consensus on the concept, we end this paper with recommendations for further research.

Accidents↗

Rationale and design of the AdRem study: evaluating the effects of blood pressure lowering and intensive glucose control on vascular retinal disorders in patients with type 2 diabetes mellitus.

The ADVANCE Retinal Measurements (AdRem) Study is a large intervention study evaluating the effects of target driven intensive glucose control and placebo controlled blood pressure lowering on retinal vascular changes. AdRem is a sub-study of the ADVANCE Study (Action in Diabetes and Vascular disease), a 2x2 factorial randomized controlled trial with an ACE inhibitor-diuretic combination (perindopril-indapamide) and a gliclazide MR-based regimen in patients with type 2 diabetes mellitus. The AdRem study is based on seven-field stereoscopic retinal photographs of both eyes. These are taken within 3 months after randomization in ADVANCE (baseline), at the biennial and at the final visit. The primary outcome is progression of two or more steps in ETDRS classification. Secondary outcomes include progression of retinal vascular lesions and distortion of retinal vascular geometry. Retinal photographs are made on film and digitized at a central laboratory. The AdRem study uses fully digitized quality control and grading. Between August 2002 and January 2004 1978 patients were included in the AdRem study, from 39 centers in 14 countries. Approximately 85% comply with the strict AdRem quality requirements. Publication of the results is expected in early 2008. The AdRem study is designed to provide reliable evidence on the effects of intensive glucose control and blood pressure lowering on both diabetic retinopathy and abnormalities of retinal vasculature in patients with type 2 diabetes mellitus.

Antihypertensive Agents↗

Noninferiority testing in cost-minimization studies: Practical issues concerning power analysis.

OBJECTIVES: In cost-minimization studies, it is important to establish noninferiority in the clinical effect of the treatments under investigation. The relationship between the proportion of patients reaching the end point in a study, equivalence limit (delta), and power is investigated in the context of cost-minimization studies with dichotomous clinical end points. Two formulations of the null-hypothesis, absolute and relative formulations of delta, will be explored. METHODS: Sensitivity analysis was performed, in which the effect of the predicted proportions and delta on the power in a noninferiority setting was investigated. The patterns found are discussed in terms of the practical relevance within the cost-minimization framework. RESULTS: Sensitivity analyses show different patterns of results for both null-hypotheses. The differences in these results originate from the way delta is expressed. By expressing delta as absolute difference, power grows quite fast when sample proportions are smaller than expected. In the case of a proportional delta at small sample proportions, the power to establish noninferiority remains low. CONCLUSIONS: To obtain valid results from a cost-minimization study, care has to be taken to adapt the correct methodology for noninferiority testing in clinical outcomes. Defining delta in terms of absolute differences between treatments can lead to obscured results. Although conservative, the expression of delta as a proportion of the effectiveness of the treatment as usual is found to be closer to clinical practice. The inflated delta, resulting from smaller clinical effects than expected when absolute formulation is applied, thus can be avoided.

Cost Control↗

The effect of moderate alcohol consumption on fat distribution and adipocytokines.

OBJECTIVE: To investigate the effect of moderate alcohol consumption on fat distribution, adipose tissue secreted proteins (adiponectin and resistin), and insulin sensitivity in healthy middle-aged men with abdominal obesity. RESEARCH METHODS AND PROCEDURES: Thirty-four healthy men between 35 and 70 years old, with increased waist circumference (> or = 94 cm), participated in a randomized, controlled cross-over design trial. They drank 450 mL of red wine (40 grams of alcohol) or 450 mL of de-alcoholized red wine daily during 4 weeks. At the end of each treatment period, fat distribution, adipose tissue proteins, and insulin sensitivity index (ISI) were measured. RESULTS: Subcutaneous and abdominal fat contents and body weight did not change after 4 weeks of moderate alcohol consumption. Liver fat (quip index) was slightly higher after consumption of red wine (6.8 +/- 0.1) as compared with de-alcoholized red wine (6.5 +/- 0.1) but not significantly different (p = 0.09). Plasma adiponectin concentration increased (p < 0.01) to 6.0 +/- 0.1 microg/mL after 28 days of moderate alcohol consumption compared with de-alcoholized red wine (5.5 +/- 0.1 microg/mL). Serum resistin concentrations and ISI were not affected by alcohol consumption. Percentage changes in serum resistin correlated significantly with changes in ISI (r = -0.69, p < 0.01), whereas this correlation was not present between changes in plasma adiponectin and ISI (r = 0.31, p = 0.22). DISCUSSION: Moderate alcohol consumption for 4 weeks is not associated with differences in subcutaneous and abdominal fat contents or body weight. Thus, the 10% increase in adiponectin was not associated with a change in fat distribution or body weight change.

Abdominal Fat↗

Are retinal microvascular abnormalities associated with large artery endothelial dysfunction and intima-media thickness? The Hoorn Study.

It has been hypothesized that microvascular dysfunction affects endothelial dysfunction of the large arteries, which may explain the relationship of microvascular disease with macrovascular disease. The aim of the present study was to investigate the relationship of retinal microvascular disorders with endothelium-dependent FMD (flow-mediated vasodilatation) and carotid IMT (intima-media thickness). A total of 256 participants, aged 60-85 years, 70 with normal glucose metabolism, 69 with impaired glucose metabolism and 109 with Type II diabetes, were included in this study. All participants were ophthalmologically examined, including funduscopy and two field 45 degrees fundus photography, and were graded for retinal sclerotic vessel abnormalities and retinopathy. Retinal arteriolar and venular diameters were measured with a computer-assisted method. Brachial artery, endothelium-dependent FMD and carotid IMT were assessed ultrasonically as measurements of endothelial function and early atherosclerosis respectively. After adjustment for age, sex and glucose tolerance status, retinal vessel diameters, retinal sclerotic vessel abnormalities and retinopathy were not significantly associated with FMD. In contrast with other retinal microvascular abnormalities, retinal venular dilatation was associated with increased IMT [standardized beta value (95% confidence interval), 0.14 (0.005-0.25)]. This association was attenuated and lost statistical significance after adjustment for cardiovascular risk factors, in particular after correction for fasting insulin. In the present study, retinal microvascular disorders are not independently associated with impaired FMD. In addition, retinal venular dilatation is associated with increased IMT, although non-significantly after multivariable adjustment for cardiovascular risk factors. Therefore our data provide evidence that retinal microvascular disease is of limited value in risk stratification for future cardiovascular events.

Aged↗

Hyperglycemia and diabetes in patients with schizophrenia or schizoaffective disorders.

OBJECTIVE: Pharmacoepidemiological studies have shown an increased prevalence of diabetes in patients with schizophrenia. To address this issue, we decided to assess glucose metabolism in a population of patients with schizophrenia or schizoaffective disorder. RESEARCH DESIGN AND METHODS: Oral glucose tolerance tests (OGTTs) were performed in 200 unselected in- and outpatients. Insulin sensitivity and beta-cell function were assessed using the homeostasis model assessment (HOMA) indexes and 30-min glucose and insulin levels. RESULTS: The mainly Western European (87.7%) study population had a mean age of 40.8 years, was 70% male, and had a mean fasting glucose of 5.1 mmol/l and a mean fasting insulin of 14.8 mU/l. Hyperglycemia was present in 7% of the population: 1.5% with impaired fasting glucose and 5.5% with impaired glucose tolerance. The prevalence of diabetes was 14.5%, of which 8% was previously known and 6.5% was newly diagnosed. Compared with a 1.5% prevalence of diabetes in the age-matched general Dutch population, the prevalence of identified cases was significantly increased in the study population. Comparable figures on the prevalence of hyperglycemia in the general population are not available. Insulin resistance was increased in the study population as a whole (HOMA of insulin resistance: 3.1-3.5), irrespective of the use of antipsychotic medication and, if used, irrespective of its type (typical or atypical). No indication of beta-cell defect was found, whereas a nonsignificant increased insulin resistance was found with antipsychotic medication. CONCLUSIONS: OGTTs in 200 mainly Caucasian patients with schizophrenia or schizoaffective disorder, mean age 41 years, showed that 7% suffered from hyperglycemia and 14.5% from diabetes. The prevalence of diabetes was significantly increased compared with the general population. No differential effect of antipsychotic monotherapy in diabetogenic effects was found. Therefore, a modification of the consensus statement on antipsychotic drugs, obesity, and diabetes is proposed, i.e., measurement of fasting glucose in all patients with schizophrenia, irrespective of prescribed antipsychotic drug.

Adult↗

High cumulative insulin exposure: a risk factor of atherosclerosis in type 1 diabetes?

BACKGROUND: Since insulin therapy might have an atherogenic effect, we studied the relationship between cumulative insulin dose and atherosclerosis in type 1 diabetes. We have focused on patients with type 1 diabetes instead of type 2 diabetes to minimise the effect of insulin resistance as a potential confounder. METHODS: An observational study was performed in 215 subjects with type 1 diabetes treated with multiple insulin injection therapy. Atherosclerosis was assessed by measurement of carotid intima-media thickness (CIMT). RESULTS: The cumulative dose of regular insulin showed a positive and significant relation with CIMT: increase of 21 microm in CIMT per S.D. of insulin use (95% CI: 8-35 adjusted for gender and age), which remained unchanged after adjustment for duration of diabetes, HbA1c, BMI, pulse pressure, physical activity and carotid lumen diameter. A similar relation was found for intermediate-acting insulin: 15.5 microm per S.D. (2-29), which was no longer present after further adjustment. CONCLUSIONS: These findings provide evidence that a high cumulative dose of regular insulin is a risk factor for atherosclerosis.

Adult↗

Alcohol consumption and risk of type 2 diabetes among older women.

OBJECTIVE: This study aimed to investigate the relation between alcohol consumption and type 2 diabetes among older women. RESEARCH DESIGN AND METHODS: Between 1993 and 1997, 16,330 women aged 49-70 years and free from diabetes were enrolled in one of the Dutch Prospect-EPIC (European Prospective Study Into Cancer and Nutrition) cohorts and followed for 6.2 years (range 0.1-10.1). At enrollment, women filled in questionnaires and blood samples were collected. RESULTS: During follow-up, 760 cases of type 2 diabetes were documented. A linear inverse association (P = 0.007) between alcohol consumption and type 2 diabetes risk was observed, adjusting for potential confounders. Compared with abstainers, the hazard ratio for type 2 diabetes was 0.86 (95% CI 0.66-1.12) for women consuming 5-30 g alcohol per week, 0.66 (0.48-0.91) for 30-70 g per week, 0.91 (0.67-1.24) for 70-140 g per week, 0.64 (0.44-0.93) for 140-210 g per week, and 0.69 (0.47-1.02) for >210 g alcohol per week. Beverage type did not influence this association. Lifetime alcohol consumption was associated with type 2 diabetes in a U-shaped fashion. CONCLUSIONS: Our findings support the evidence of a decreased risk of type 2 diabetes with moderate alcohol consumption and expand this to a population of older women.

Aged↗

Antihypertensive drug therapy and the risk of lower extremity amputations in pharmacologically treated type 2 diabetes patients.

PURPOSE: The objective of this study was to determine the association between different antihypertensive drug therapies and lower extremity amputations (LEAs) in type 2 diabetes patients. METHODS: Data were obtained from the PHARMO Record Linkage System comprising pharmacy records and data on hospitalisations for all 450,000 residents of eight Dutch cities. In a nested case-control study among 12,140 type 2 diabetes patients who used antihypertensive drugs, 26 cases with a first LEA and 94 controls without a LEA matched on age, sex and calendar time were identified. Logistic regression was used to estimate the relative risk of LEA and to adjust for potential confounding factors. RESULTS: Among type 2 diabetes patients who used antihypertensive drugs, subjects who used thiazide diuretics, alone or in combination, had a higher risk of LEA compared to subjects who used Angiotensin Converting Enzyme (ACE) inhibitor monotherapy (crude odds ratio (OR): 6.11 [95% confidence interval (CI): 1.32-28.27]). The use of thiazide diuretics was also associated with an increased risk of LEA when compared to the use of any non-thiazide antihypertensive drug (adjusted OR: 7.04 [1.10-45.30]). The increased risk of LEA associated with the use of thiazides compared to the use of non-thiazides depended on the duration of use (adjusted OR(< or = 365 days), 4.82 [0.61-38.34] and adjusted OR(>365 days), 26.16 [1.02-674.02], p-trend = 0.01). CONCLUSIONS: Treatment with thiazide diuretics compared to treatment with other antihypertensive drugs was associated with excess amputations in type 2 diabetes patients. Due to several limitations of this study, our findings do not preclude the use of thiazides in type 2 diabetes mellitus patients as yet.

Aged↗

History taking and leukocyturia predict the presence of asymptomatic bacteriuria in women with diabetes mellitus.

OBJECTIVE: To investigate the accuracy of history taking to diagnose asymptomatic bacteriuria (ASB) in diabetic women, and the added value of leukocyturia. METHODS: Data were obtained from a multicenter study including 465 women with diabetes. Many patient characteristics were considered as potential diagnostic determinants. A urinary leukocyte count and a urine culture (the criterion standard) were performed. Logistic regression analyses were performed and areas under the receiver operating characteristic curves (AUC) were calculated. RESULTS: For women with type 1 diabetes (n = 236; ASB 11%), duration of diabetes and glycosylated hemoglobin (GHb) were powerful predictors of ASB. The AUC of the model including these two variables was 0.66 (95% confidence interval (CI) 0.53-0.78). After addition of leukocyturia, the AUC increased considerably to 0.78 (95% CI 0.68-0.88; p = 0.018). For women with type 2 diabetes (n = 229; ASB 19%), age and the number of symptomatic urinary tract infections (UTIs) in the previous year were the strongest predictors of ASB. The AUC of the model including these variables was 0.70 (95% CI 0.61-0.80). After addition of leukocyturia, the AUC increased to 0.79 (95% CI 0.71-0.86; p = 0.023). CONCLUSION: In diabetic women, ASB can be diagnosed using two easily obtainable variables (duration of diabetes and GHb for women with type 1 diabetes, and age and the number of UTIs in the previous year for women with type 2 diabetes) in combination with a urinary leukocyte count. This results in a model with sufficient accuracy (AUC > 0.75).

Adult↗

alpha-Tocopherol levels in plasma in new-onset, insulin-dependent diabetes mellitus.

BACKGROUND: Diabetic complications have been related to increased oxidative stress. Plasma antioxidant levels may be affected by hyperglycemia-induced oxidative stress as well as by insulin therapy. We evaluated the immediate effect of insulin treatment and improved metabolic control on the important antioxidant alpha-tocopherol plasma (vitamin E) levels in new-onset, insulin-dependent diabetes mellitus. METHODS: The study was performed in 15 consecutive patients, aged 20-67 years, with new-onset diabetes mellitus requiring acute insulin treatment. Plasma alpha-tocopherol levels were measured before the start of intensive insulin treatment and monthly for 6 months thereafter. Simultaneously, we studied plasma malondialdehyde (MDA) as a reflection of lipid peroxidation. In addition, comparisons were made to a nondiabetic reference group. RESULTS: Baseline alpha-tocopherol levels did not differ from those in nondiabetic subjects. alpha-Tocopherol decreased significantly, from 33.5+/-12.1 mumol/l before treatment to 28.11+/-6.85 mumol/l (-16%) after 1 month of insulin therapy (p<0.04) to 26.6+/-7.03 mumol/l (-20%) after 3 months of insulin therapy (p<0.02). This trend did not change after adjusting for variations in cholesterol levels. After 6 months, alpha-tocopherol was no longer decreased compared to baseline levels (29.6+/-7.4 mumol/l). MDA concentrations at baseline were significantly higher in the diabetic patients (3.79+/-2.91 mumol/l) than in the nondiabetic subjects (1.57+/-0.21 mumol/l, p=0.006). MDA concentrations decreased significantly following the start of insulin treatment. CONCLUSIONS: Patients with new-onset, insulin-dependent diabetes mellitus have alpha-tocopherol levels that are similar to those in normal subjects. Insulin treatment and/or improved metabolic control cause a significant decrease in alpha-tocopherol levels during the first months.

Journal Article↗

Patient characteristics do not predict poor glycaemic control in type 2 diabetes patients treated in primary care.

Many diabetic patients in general practice do not achieve good glycaemic control. The aim of this study was to assess which characteristics of type 2 diabetes patients treated in primary care predict poor glycaemic control (HbA1c > or = 7%). Data were collected from the medical records. 1641 patients were included who had mean HbA1c 7.1(SD 1.7)% , and 42% had HbA1c > or = 7%. On univariate analysis younger age; longer duration of diabetes; higher levels of blood glucose at diagnosis; most recent fasting blood glucose (FBG), total cholesterol, and triglyceride; higher body mass index (BMI); treatment with oral hypoglycaemic agents (OHA); treatment with insulin; more GP-visits for diabetes in the last year; and lower educational level were associated with poor control. Both in multiple linear regression and in multiple logistic regression higher levels of FBG (odds ratio (OR): = 1.6, 95% confidence interval (CI): 1.49, 1.70), treatment with OHA (OR: 2.1, 95% CI: 1.41, 3.04), treatment with insulin (OR: 7.2, 95% CI: 4.18, 12.52), lower educational level (OR: 1.26, 95% CI: 1.01, 1.56) were independently associated with poor levels of HbA1c. When FBG levels were excluded from the model, higher blood glucose at diagnosis, higher values for triglyceride and total cholesterol, and younger age predicted poor glycaemic control, but these variables explained only 15% of the variation in HbA1c. In conclusion prediction of poor glycaemic control from patient characteristics in diabetic patients in general practice is hardly possible. FBG appeared to be a strong predictor of HbA1c, which underlines the usefulness of this simple test in daily diabetes care. The worse metabolic control in those treated with either OHA or insulin suggests that current treatment regimes might be not sufficiently applied to reach the targets of care. Providers of diabetes care should be attentive to patients with lower educational level.

Age Factors↗

Antipsychotic drugs may worsen metabolic control in type 2 diabetes mellitus.

BACKGROUND: Several studies have indicated that type 2 diabetes mellitus is more common among schizophrenic patients than in the general population. In this study, we investigated whether the use of antipsychotic drugs in patients with diabetes leads to worsening of glycemic control. METHOD: In this cohort study, patients with newly diagnosed type 2 diabetes were selected from the PHARMO Record Linkage System, which comprises pharmacy records for all 320000 residents of 6 Dutch cities. In total, we identified 2585 patients with incident cases of type 2 diabetes who began treatment with oral hypoglycemic agents between 1991 and 1997 and had a medication history of at least 2 years after diagnosis of diabetes. A change in treatment from oral hypoglycemic agents alone to insulin therapy (with or without continuation of oral hypoglycemic agents) was considered a proxy for deterioration of beta-cell function. We compared the incidence of initiation of insulin therapy between users and nonusers of antipsychotic drugs by performing a Cox proportional hazards model analysis. RESULTS: We found an increased risk for initiation of insulin therapy at 2 years after diagnosis of diabetes in users of antipsychotics compared with nonusers; the relative hazard (hazard ratio) was 2.0 (95% CI = 1.2 to 3.3), which did not change after adjustment for potential confounders. The risk decreased in the years after diagnosis of diabetes. CONCLUSION: It seems that use of antipsychotics by patients with type 2 diabetes mellitus is associated with initiation of insulin therapy (i.e., "secondary failure"), especially in the first 2 years of the disease.

Antipsychotic Agents↗

Starting insulin in type 2 diabetes: continue oral hypoglycemic agents? A randomized trial in primary care.

OBJECTIVE: To evaluate the effects of insulin 30/70 twice daily or bedtime isophane (NPH) insulin plus continued sulfonylurea and metformin in patients with type 2 diabetes in primary care. STUDY DESIGN: Open-label, randomized trial. POPULATION: Persons younger than 76 years with type 2 diabetes whose disease had not been controlled with oral hypoglycemic agents alone. A total of 64 insulin-naive patients treated with maximal feasible dosages of sulfonylurea and metformin (baseline glycosylated hemoglobin [HbA1c]=8.5%) were randomly assigned to insulin monotherapy (IM group; n=31) or insulin in addition to unchanged oral hypoglycemic medication (IC group; n=33) for 12 months. Insulin doses were adjusted to obtain fasting glucose <7.0 mmol/L and postprandial glucose <10.0 mmol/L. OUTCOMES MEASURED: Outcome measures included HbA1c, treatment failure, weight, hypoglycemic events and symptoms, satisfaction with treatment, general well-being, and fear of injecting insulin and testing. RESULTS: HbA1c improved from 8.3% to 7.6% in the IC group, and from 8.8% to 7.6% in the IM group (P=NS). The IC group had 24% treatment failures, compared with 2% in the IM group (P=.09). Patients in the IC group had less weight gain than those in the IM group (1.3 vs 4.2 kg; P=.01), and they reported fewer hypoglycemic events (2.7 vs 4.3; P=.02). Increased satisfaction with treatment was equal in the 2 groups, and general well-being improved by 3.0 points more in the IC group (P=.05). Fear of self-injecting and self-testing did not differ. CONCLUSIONS: Bedtime NPH insulin added to maximal therapy with sulfonylurea and metformin is an effective, simple, well-tolerated approach for patients with uncontrolled type 2 diabetes.

Analysis of Variance↗

Refill compliance in type 2 diabetes mellitus: a predictor of switching to insulin therapy?

OBJECTIVE: To assess whether switching to insulin therapy in patients with type 2 diabetes mellitus is associated with medication refill compliance of oral hypoglycemic agents. RESEARCH DESIGN AND METHODS: The PHARMO Record Linkage System was used as data source for this study. Patients with newly treated type 2 diabetes mellitus were defined as subjects in whom oral hypoglycemic therapy was initiated between 1991 and 1998. We performed a matched case-control study in this cohort. Cases were patients who switched to insulin therapy. Date of switching in the case was defined as the index date. Controls were subjects still on oral therapy on the index date, matched on duration of diabetes and calendar time. We measured the medication refill compliance in the year starting 18 months before the index date and calculated various compliance indices. RESULTS: In total, 411 cases and 411 matched controls were identified. Cases suffered more often from more severe comorbidity and used a higher number of oral hypoglycemic agents and concomitant non-diabetic drugs. The overall compliance rate did not differ significantly between cases and controls, the adjusted odds ratio (OR) was 1.3 (CI 95% 0.6-2.8). After performing multivariate logistic regression modeling, age at onset of diabetes, gender, comedication, combination therapy, and daily dosage frequency, were independently related to switching. CONCLUSIONS: We were unable to confirm the hypothesis that noncompliance with treatment is more prevalent in patients with secondary failure. Other variables, like comorbidity and disease-related factors seem to play a more important role in switching to insulin therapy.

Administration, Oral↗