Association of practice size and pay-for-performance incentives with the quality of diabetes management in primary care

Background:

Not enough is known about the association between practice size and clinical outcomes in primary care. We examined this association between 1997 and 2005, in addition to the impact of the Quality and Outcomes Framework, a pay-for-performance incentive scheme introduced in the United Kingdom in 2004, on diabetes management.

Methods:

We conducted a retrospective open-cohort study using data from the General Practice Research Database. We enrolled 422 general practices providing care for 154 945 patients with diabetes. Our primary outcome measures were the achievement of national treatment targets for blood pressure, glycated hemoglobin (HbA_1c) levels and total cholesterol.

Results:

We saw improvements in the recording of process of care measures, prescribing and achieving intermediate outcomes in all practice sizes during the study period. We saw improvement in reaching national targets after the introduction of the Quality and Outcomes Framework. These improvements significantly exceeded the underlying trends in all practice sizes for achieving targets for cholesterol level and blood pressure, but not for HbA_1c level. In 1997 and 2005, there were no significant differences between the smallest and largest practices in achieving targets for blood pressure (1997 odds ratio [OR] 0.98, 95% confidence interval [CI] 0.82 to 1.16; 2005 OR 0.92, 95% CI 0.80 to 1.06 in 2005), cholesterol level (1997 OR 0.94, 95% CI 0.76 to 1.16; 2005 OR 1.1, 95% CI 0.97 to 1.40) and glycated hemoglobin level (1997 OR 0.79, 95% CI 0.55 to 1.14; 2005 OR 1.05, 95% CI 0.93 to 1.19).

Interpretation:

We found no evidence that size of practice is associated with the quality of diabetes management in primary care. Pay-for-performance programs appear to benefit both large and small practices to a similar extent.There is a well-established body of literature showing positive associations between volume of patients and clinical outcomes in health care, which has been documented by a systematic review.¹ However, this association has usually been examined in a limited number of discrete procedures, and most studies have involved hospital-based services rather than primary care settings.^2–5Improving our understanding of the association between volume of patients and outcomes in primary care is important for several reasons. First, most contacts with health systems occur in primary care settings, and optimizing the delivery of these services has the potential to improve the health of the population.⁶ Second, over the past decade, primary care has assumed greater responsibility for managing the growing burden of chronic disease.^7,8 Larger providers may be better resourced, through the employment of additional support staff and greater use of information technology, to deliver the systematic, structured care necessary for the effective management of chronic disease.^6,9 Third, larger providers may have been more responsive to nonfinancial and financial incentives, including pay for performance, implemented by payers aimed at improving the quality of care.^7,10 Fourth, in many countries, primary care is based around a predominance of small practices.^6,11,12 In 2006, 53% of practices in England and Wales had three or fewer family physicians.¹¹ In the same year in the United States, 30.3% of family physicians were in solo practice; 9.4% were in two-physician practices.¹²Despite the limited data available, concerns have been raised about the standards of care delivered by smaller family practices.¹³ In the United Kingdom and Canada, this has resulted in an explicit policy objective of encouraging smaller practices to amalgamate.^13,14Our study examines the associations between the size of practice and the quality of diabetes management in UK primary care settings between 1997 and 2005. We tested the hypotheses that patients attending larger family practices receive better care for diabetes and that the quality gap between larger and smaller practices has increased over the past decade. We also hypothesized that larger practices derived more benefit from the Quality and Outcomes Framework, a major pay-for-performance program in primary care introduced in 2004.     

Early Emergence of Ethnic Differences in Type 2 Diabetes Precursors in the UK: The Child Heart and Health Study in England (CHASE Study)

Background

Adults of South Asian origin living in the United Kingdom have high risks of type 2 diabetes and central obesity; raised circulating insulin, triglyceride, and C-reactive protein concentrations; and low HDL-cholesterol when compared with white Europeans. Adults of African-Caribbean origin living in the UK have smaller increases in type 2 diabetes risk, raised circulating insulin and HDL-cholesterol, and low triglyceride and C-reactive protein concentrations. We examined whether corresponding ethnic differences were apparent in childhood.

Methods and Findings

We performed a cross-sectional survey of 4,796 children aged 9–10 y in three UK cities who had anthropometric measurements (68% response) and provided blood samples (58% response); ethnicity was based on parental definition. In age-adjusted comparisons with white Europeans (n = 1,153), South Asian children (n = 1,306) had higher glycated haemoglobin (HbA1c) (% difference: 2.1, 95% CI 1.6 to 2.7), fasting insulin (% difference 30.0, 95% CI 23.4 to 36.9), triglyceride (% difference 12.9, 95% CI 9.4 to 16.5), and C-reactive protein (% difference 43.3, 95% CI 28.6 to 59.7), and lower HDL-cholesterol (% difference −2.9, 95% CI −4.5 to −1.3). Higher adiposity levels among South Asians (based on skinfolds and bioimpedance) did not account for these patterns. Black African-Caribbean children (n = 1,215) had higher levels of HbA1c, insulin, and C-reactive protein than white Europeans, though the ethnic differences were not as marked as in South Asians. Black African-Caribbean children had higher HDL-cholesterol and lower triglyceride levels than white Europeans; adiposity markers were not increased.

Conclusions

Ethnic differences in type 2 diabetes precursors, mostly following adult patterns, are apparent in UK children in the first decade. Some key determinants operate before adult life and may provide scope for early prevention. Please see later in the article for the Editors'' Summary     

Nonalcoholic Fatty Liver Disease and Risk of Diabetes: A Prospective Study in China

Objective: We aimed to investigate whether liver steatosis severity affects the risk of developing diabetes in a large cohort study.Methods: We prospectively examined the association in 41,650 Chinese adults with negative hepatitis-B surface antigen who were free of alcohol consumption, diabetes, and liver cirrhosis at baseline. Cox proportional models were used to estimate the risk of diabetes after a mean of 3.6 years of follow-up. Nonalcoholic fatty liver disease (NAFLD) was assessed with hepatic ultrasonography. Elevated alanine transaminase (ALT) was defined as ALT concentrations >19 and >30 U/L in females and males, respectively. Diabetes was defined as a fasting glucose ³7.0 mmol/L or treatment with hypoglycemic medication.Results: Liver steatosis severity was significantly associated with higher risks of developing diabetes (adjusted hazard ratio [HR] for severe vs. without NAFLD = 2.66, 95% confidence interval [CI]: 2.17–3.25, P-trend<.001) and impaired fasting glucose (fasting glucose between 5.6 and 6.9 mmol/L, adjusted HR = 1.36, 95% CI: 1.16–1.59, P-trend<.001), as well as a faster increase rate of fasting glucose concentrations (P-trend<.001), during 3.6 years of follow-up. Elevated ALT was also associated with incident diabetes (HR = 1.12, 95% CI: 1.02–1.22), adjusting for NAFLD and other covariates.Conclusion: We observed a dose-response relationship between liver steatosis severity and increased diabetes risk, and ALT may predict incident diabetes independently of NAFLD.Abbreviations: ALT = alanine transaminase; BP = blood pressure; CI = confidence interval; HCV = hepatitis C virus; HR = hazard ratio; IFG = impaired fasting glucose; NAFLD = nonalcoholic fatty liver disease; ULN = upper limit of normal     

History of Having a Macrosomic Infant and the Risk of Diabetes: The Japan Public Health Center-Based Prospective Diabetes Study

Objective

The aim of the present study was to test a hypothesis that a history of having a macrosomic infant (≥4000g) is associated with the risk of diabetes.

Methods

Data on the Japan Public Health Center-based Prospective diabetes cohort were analyzed, which is a population-based cohort study on diabetes. The survey of diabetes was performed at baseline and at the 5-year follow-up. A history of having a macrosomic infant was assessed using a self-administered questionnaire. A cross-sectional analysis was performed among 12,153 women who participated in the 5-year survey of the cohort. Logistic regression was used to examine the relationship between a history of having a macrosomic infant and the presence of diabetes. A longitudinal analysis was also conducted among 7,300 women without diabetes who participated in the baseline survey. Logistic regression was used to investigate the relationship between a history of having a macrosomic infant and the incidence of diabetes between the baseline survey and the 5-year survey.

Results

In the cross-sectional analysis, parous women with a positive history were more likely to have diabetes in relation to parous women without (OR = 1.44, 95% CI = 1.13-1.83). The longitudinal analysis showed a modest but non-significant increased risk of developing diabetes among women with a positive history (OR = 1.24, 95% CI = 0.80-1.94).

Conclusions

An increased risk of diabetes was implied among women with a history of having a macrosomic infant although the longitudinal analysis showed a non-significant increased risk.     

Ethnic disparities in estimated cardiovascular disease risk in Amsterdam,the Netherlands

Background

Ethnic differences have been reported in cardiovascular disease (CVD) risk factors. It is still unclear which ethnic groups are most at risk for CVD when all traditional CVD risk factors are considered together as overall risk.

Objectives

To examine ethnic differences in overall estimated CVD risk and the risk factors that contribute to these differences.

Design

Using data of the multi-ethnic HELIUS study (HEalthy LIfe in an Urban Setting) from Amsterdam, we examined whether estimated CVD risk and risk factors among those eligible for CVD risk estimation differed between participants of Dutch, South Asian Surinamese, African Surinamese, Ghanaian, Turkish and Moroccan origin. Using the Systematic COronary Risk Evaluation (SCORE) algorithm, we estimated risk of fatal CVD and risk of fatal plus non-fatal CVD. These risks were compared between ethnic groups via age-adjusted linear regression analyses.

Results

The SCORE algorithm was applicable to 9,128 participants. Relative to the fatal CVD risk of participants of Dutch origin, South Asian Surinamese participants showed a higher fatal CVD risk, Ghanaian males a lower fatal CVD risk, and participants of other ethnic origins a similar fatal CVD risk. For fatal plus non-fatal CVD risk, African Surinamese and Turkish men also showed a higher risk. When diabetes was incorporated in the CVD risk algorithm, all but Ghanaian men showed a higher CVD risk relative to the participants of Dutch origin (betas ranging from 0.98–3.10%). The CVD risk factors that contribute the most to these ethnic differences varied between ethnic groups.

Conclusion

Ethnic minority groups are at a greater estimated risk of fatal plus non-fatal CVD relative to the group of native Dutch. Further research is necessary to determine whether this will translate to ethnic differences in CVD incidence and, if so, whether ethnic-specific CVD prevention strategies are warranted.

     

Understanding the Relationship between Type 2 Diabetes Mellitus and Falls in Older Adults: A Prospective Cohort Study

Background

Older adults with type 2 Diabetes Mellitus are at increased risk of falling. The current study aims to identify risk factors that mediate the relationship between diabetes and falls.

Methods

199 older adults (104 with diabetes and 95 healthy controls) underwent a medical screening. Gait (GAITRite®), balance (AccuGait® force plate), grip strength (Jamar®), and cognitive status (Mini-Mental State Examination and Clock Drawing Test) were assessed. Falls were prospectively recorded during a 12-month follow-up period using monthly calendars.

Results

Compared to controls, diabetes participants scored worse on all physical and cognitive measures. Sixty-four participants (42 diabetes vs. 22 controls) reported at least one injurious fall or two non-injurious falls (“fallers”). Univariate logistic regression identified diabetes as a risk factor for future falls (Odds Ratio 2.25, 95%CI 1.21–4.15, p = 0.010). Stepwise multiple regressions defined diabetes and poor balance as independent risk factors for falling. Taking more medications, slower walking speed, shorter stride length and poor cognitive performance were mediators that reduced the Odds Ratio of the relationship between diabetes and faller status relationship the most followed by reduced grip strength and increased stride length variability.

Conclusions

Diabetes is a major risk factor for falling, even after controlling for poor balance. Taking more medications, poorer walking performance and reduced cognitive functioning were mediators of the relationship between diabetes and falls. Tailored preventive programs including systematic medication reviews, specific balance exercises and cognitive training might be beneficial in reducing fall risk in older adults suffering from diabetes.     

Associations of Maternal Diabetes During Pregnancy with Overweight in Offspring: Results from the Prospective TEDDY Study

Objective: This study aimed to determine the relationship between different forms of, and potential pathways between, maternal diabetes and childhood obesity at different ages. Methods: Prospective cohort data from The Environmental Determinants of Diabetes in the Young (TEDDY) study, which was composed of 5,324 children examined from 0.25 to 6 years of age, were analyzed. Cross‐sectional and longitudinal analyses taking into account potential confounders and effect modifiers such as maternal prepregnancy BMI and birth weight z scores were performed. Results: Offspring of mothers with gestational diabetes mellitus (GDM) or type 1 diabetes mellitus (T1DM) showed a higher BMI standard deviation score and increased risk for overweight and obesity at 5.5 years of age than offspring of mothers without diabetes. While these associations could be substantially explained by maternal prepregnancy BMI in offspring of mothers with GDM, significant associations disappeared after adjustment for birth weight z scores in offspring of T1DM mothers. Furthermore, overweight risk became stronger with increasing age in offspring of mothers with diabetes compared with offspring of mothers without diabetes. Conclusions: Maternal diabetes is associated with increased risk of offspring overweight, and the association appears to get stronger as children grow older. Indeed, intrauterine exposure to maternal T1DM may predispose children to later obesity through increased birth weight, while maternal BMI is more important in children exposed to GDM.     

NHS Diabetes guideline for the perioperative management of the adult patient with diabetes

These Joint British Diabetes Societies guidelines, commissioned by NHS Diabetes, for the perioperative management of the adult patient undergoing surgery are available in full in the Supporting Information. This document goes through the seven stages of the patient journey when having surgery. These are: primary care referral; surgical outpatients; preoperative assessment; hospital admission; surgery; post-operative care; discharge. Each stage is given its own considerations, outlining the roles and responsibilities of each group of healthcare professionals. The evidence base for the recommendations made at each stage, discussion of controversial areas and references are provided in the report. This document has two key recommendations. Firstly, that the management of the elective adult surgery patients should be with modification to their usual diabetes treatment if the fasting is minimized because the routine use of a variable rate intravenous insulin infusion is not recommended. Secondly, that poor preoperative glycaemic control leads to post-outcomes and thus, where appropriate, needs to be addressed prior to referral for surgery.     

Association of Diabetes and Prognosis of Minor Stroke and Its Subtypes: A Prospective Observational Study

BackgroundThe association between diabetes mellitus (DM) and prognosis of minor stroke is unclear. The aim of this study is to investigate whether DM contributes to the prognosis of minor stroke or its specific subtype.MethodsAll minor ischemic stroke patients were derived from the China National Stroke Registry and classified into 5 subtypes according to the TOAST (Trial of Org 10172 in Acute Stroke Treatment) criteria. DM was defined as either self-reported physician diagnosis of diabetes or use of hypoglycemic medications during hospitalization or at discharge. Patients were followed up for 1 year for clinical outcomes of recurrent stroke, death and functional outcome. Poor functional outcomes were defined as a score of 2–6 for modified Rankin Score. Associations between DM and prognosis of minor stroke and its subtypes were analyzed by univariable and multivariable logistic regression.ResultsOf 4,548 patients with minor stroke, 1,230(27.0%) patients had DM, 1,038(22.8%) had poor outcomes and 570(13.0%) of 4,401 patients had recurrent stroke at 1 year. In multivariable analyses, DM were significantly associated with 1-year stroke recurrence (Odds Ratio [OR], 1.31; 95% confidence interval [CI]: 1.08–1.59) and poor outcome (OR, 1.51; 95%CI: 1.28–1.77). Among the subtypes of minor stroke, DM was only significantly associated with 1-year stroke recurrence (OR, 1.63; 95%CI: 1.07–2.50) and poor outcome (OR, 1.73; 95%CI: 1.22–2.45) in the small-artery occlusion subtype.ConclusionsDM significantly increased the risk of stroke recurrence and poor outcome in the small-artery occlusion subtype, but not in other subtypes of minor stroke.     

Consequences of Gestational Diabetes in an Urban Hospital in Viet Nam: A Prospective Cohort Study

Background

Gestational diabetes mellitus (GDM) is increasing and is a risk for type 2 diabetes. Evidence supporting screening comes mostly from high-income countries. We aimed to determine prevalence and outcomes in urban Viet Nam. We compared the proposed International Association of the Diabetes and Pregnancy Study Groups (IADPSG) criterion, requiring one positive value on the 75-g glucose tolerance test, to the 2010 American Diabetes Association (ADA) criterion, requiring two positive values.

Methods and Findings

We conducted a prospective cohort study in Ho Chi Minh City, Viet Nam. Study participants were 2,772 women undergoing routine prenatal care who underwent a 75-g glucose tolerance test and interview around 28 (range 24–32) wk. GDM diagnosed by the ADA criterion was treated by local protocol. Women with GDM by the IADPSG criterion but not the ADA criterion were termed “borderline” and received standard care. 2,702 women (97.5% of cohort) were followed until discharge after delivery. GDM was diagnosed in 164 participants (6.1%) by the ADA criterion, 550 (20.3%) by the IADPSG criterion. Mean body mass index was 20.45 kg/m² in women with out GDM, 21.10 in women with borderline GDM, and 21.81 in women with GDM, p<0.001. Women with GDM and borderline GDM were more likely to deliver preterm, with adjusted odds ratios (aORs) of 1.49 (95% CI 1.16–1.91) and 1.52 (1.03–2.24), respectively. They were more likely to have clinical neonatal hypoglycaemia, aORs of 4.94 (3.41–7.14) and 3.34 (1.41–7.89), respectively. For large for gestational age, the aORs were 1.16 (0.93–1.45) and 1.31 (0.96–1.79), respectively. There was no significant difference in large for gestational age, death, severe birth trauma, or maternal morbidity between the groups. Women with GDM underwent more labour inductions, aOR 1.51 (1.08–2.11).

Conclusions

Choice of criterion greatly affects GDM prevalence in Viet Nam. Women with GDM by the IADPSG criterion were at risk of preterm delivery and neonatal hypoglycaemia, although this criterion resulted in 20% of pregnant women being positive for GDM. The ability to cope with such a large number of cases and prevent associated adverse outcomes needs to be demonstrated before recommending widespread screening. Please see later in the article for the Editors'' Summary.     

Prospective validation of American Diabetes Association risk tool for predicting pre-diabetes and diabetes in Taiwan-Taichung community health study

Background

A simple diabetes risk tool that does not require laboratory tests would be beneficial in screening individuals at higher risk. Few studies have evaluated the ability of these tools to identify new cases of pre-diabetes. This study aimed to assess the ability of the American Diabetes Association Risk Tool (ADART) to predict the 3-year incidence of pre-diabetes and diabetes in Taiwanese.

Methods

This was a 3-year prospective study of 1021 residents with normoglycemia at baseline, gathered from a random sample of residents aged 40–88 years in a metropolitan city in Taiwan. The areas under the curve (AUCs) of three models were compared: ADART only, ADART plus lifestyle behaviors at baseline, and ADART plus lifestyle behaviors and biomarkers at baseline. The performance of ADART was compared with that of 16 tools that had been reported in the literature.

Results

The AUCs and their 95% confidence intervals (CIs) were 0.60 (0.54–0.66) for men and 0.72 (0.66–0.77) for women in model 1; 0.62 (0.56–0.68) for men and 0.74 (0.68–0.80) for women in model 2; and 0.64 (0.58–0.71) for men and 0.75 (0.69–0.80) for women in model 3. The AUCs of these three models were all above 0.7 in women, but not in men. No significant difference in either women or men (p = 0.268 and 0.156, respectively) was observed in the AUC of these three models. Compared to 16 tools published in the literature, ADART had the second largest AUC in both men and women.

Conclusions

ADART is a good screening tool for predicting the three-year incidence of pre-diabetes and diabetes in females of a Taiwanese population. The performance of ADART in men was similar to the results with other tools published in the literature. Its performance was one of the best among the tools reported in the literature.     

Ethnic variations in the prevalence of diabetic retinopathy in people with diabetes attending screening in the United Kingdom (DRIVE UK)

Aims

To compare the prevalence of diabetic retinopathy (DR) in people of various ethnic groups with diabetes in the United Kingdom (UK).

Methods

The Diabetic Retinopathy In Various Ethnic groups in UK (DRIVE UK) Study is a cross-sectional study on the ethnic variations of the prevalence of DR and visual impairment in two multi-racial cohorts in the UK. People on the diabetes register in West Yorkshire and South East London who were screened, treated or monitored between April 2008 to July 2009 (London) or August 2009 (West Yorkshire) were included in the study. Data included age, sex, ethnic group, type of diabetes, presenting visual acuity and the results of grading of diabetic retinopathy. Prevalence estimates for the ethnic groups were age-standardised to the white European population for comparison purposes.

Results

Out of 57,144 people on the two diabetic registers, data were available on 50,285 individuals (88.0%), of these 3,323 had type 1 and 46,962 had type 2 diabetes. In type 2 diabetes, the prevalence of any DR was 38.0% (95% confidence interval(CI) 37.4% to 38.5%) in white Europeans compared to 52.4% (51.2% to 53.6%) in African/Afro-Caribbeans and 42.3% (40.3% to 44.2%) in South Asians. Similarly, sight threatening DR was also significantly more prevalent in Afro-Caribbeans (11.5%, 95% CI 10.7% to 12.3%) and South Asians (10.3%, 9.0% to 11.5%) compared to white Europeans (5.5%, 5.3% to 5.8%). Differences observed in Type 1 diabetes did not achieve conventional levels of statistical significance, but there were lower numbers for these analyses.

Conclusions

Minority ethnic communities with type 2 diabetes in the UK are more prone to diabetic retinopathy, including sight-threatening retinopathy and maculopathy compared to white Europeans.     

Total and Differential Leukocyte Counts in Relation to Incidence of Diabetes Mellitus: A Prospective Population-Based Cohort Study

Objective

High concentrations of leukocytes in blood have been associated with diabetes mellitus. This prospective study aimed to explore whether total and differential leukocyte counts are associated with incidence of diabetes. A missense variant R262W in the SH2B3 (SH2B adaptor protein 3) gene, coding for a protein that negatively regulates hematopoietic cell proliferation, was also studied in relation to incidence of diabetes.

Methods and Results

Leukocyte count and its subtypes (neutrophils, lymphocytes and mixed cells) were analyzed in 26,667 men and women, 45–73 years old, from the population-based Malmö Diet and Cancer study. Information about the R262W polymorphism (rs3184504) in SH2B3 was genotyped in 24,489 subjects. Incidence of diabetes was studied during a mean follow-up of 14 years. Cox proportional hazards regression was used to examine incidence of diabetes by total and differential leukocyte counts. Mendelian randomization analysis using R262W as an instrumental variable was performed with two-stage least squares regression. A total of 2,946 subjects developed diabetes during the follow-up period. After taking several possible confounders into account, concentrations of total leukocyte count, neutrophils and lymphocytes were all significantly associated with incidence of diabetes. The adjusted hazard ratios (95% confidence interval; quartile 4 vs quartile 1) were 1.37 (1.22–1.53) for total leukocytes, 1.33 (1.19–1.49) for neutrophils and 1.29 (1.15–1.44) for lymphocytes. The R262W polymorphism was strongly associated with leukocytes (0.11x10⁹ cells/l per T allele, p = 1.14 x10^-12), lymphocytes (p = 4.3 x10^-16), neutrophils (p = 8.0 x10^-6) and mixed cells (p = 3.0 x10^-6). However, there was no significant association between R262W and fasting glucose, HbA_1c or incidence of diabetes.

Conclusions

Concentrations of total leukocytes, neutrophils and lymphocytes are associated with incidence of diabetes. However, the lack of association with the R262W polymorphism suggests that the associations may not be causal, although limitations in statistical power and balancing pleiotropic effects cannot be excluded.     

Obesity and Life Expectancy with and without Diabetes in Adults Aged 55 Years and Older in the Netherlands: A Prospective Cohort Study

BackgroundOverweight and obesity are associated with increased risk of type 2 diabetes. Limited evidence exists regarding the effect of excess weight on years lived with and without diabetes. We aimed to determine the association of overweight and obesity with the number of years lived with and without diabetes in a middle-aged and elderly population.ConclusionsObesity in the middle aged and elderly is associated with a reduction in the number of years lived free of diabetes and an increase in the number of years lived with diabetes. Those extra years lived with morbidity might place a high toll on individuals and health care systems.     

The Association of Handgrip Strength and Type 2 Diabetes Mellitus in Six Ethnic Groups: An Analysis of the HELIUS Study

We investigated whether ethnic differences in handgrip strength, a marker of poor muscle strength and quality, is a potential cause of ethnic disparities in type 2 diabetes mellitus. We included 2086 Dutch, 2216 South Asian Surinamese, 2084 African Surinamese, 1786 Ghanaian, 2223 Turkish and 2199 Moroccan origin participants from the HELIUS study. We analyzed ethnic differences in handgrip strength, and its association with type 2 diabetes mellitus using logistic regression analyses adjusted for socio-demographic factors, body composition and lifestyle factors. Additionally, we investigated whether handgrip strength explained the ethnic differences in type 2 diabetes mellitus. We found that handgrip strength differed significantly across ethnic groups. After full adjustment, we found an inverse association with type 2 diabetes mellitus (OR 0.95; 95% CI 0.92–0.97) that did not differ substantially between ethnic groups, men and among women, and lean and overweight individuals. The association was not affected by the measure used to define type 2 diabetes mellitus, but was attenuated by exclusion of people with known diabetes. The ethnic differences in type 2 diabetes mellitus were not explained by handgrip strength (e.g. the OR for the South Asian Surinamese vs. Dutch changed from 5.03; 3.69–6.68 to 4.87; 3.57–6.65). In conclusion, we found large ethnic differences in handgrip strength and a consistent association of low handgrip strength with prevalent type 2 diabetes mellitus. This suggests that handgrip strength may be investigated as a target for intervention or a marker to identify people at risk of type 2 diabetes mellitus.