Cardiovascular disease guideline adherence and self-reported statin use in longstanding type 1 diabetes: results from the Canadian study of longevity in diabetes cohort

Impact of statin treatment on cardiovascular risk in patients with type 1 diabetes: a population-based cohort study

BACKGROUND

Cardiovascular disease (CVD) is a major complication in type 1 diabetes mellitus (T1D) patients. Previous studies have suggested that statins may be helpful for prevention of CVD in T1D, but there are limited data on the role of statins in T1D. We investigated the relationship between statin treatment and cardiovascular risk in T1D patients using a population-based cohort.

METHODS

We conducted a retrospective cohort study using the Korean nationwide health insurance database from January 2007 to December 2017. This study included 11,009 T1D patients aged ≥ 20 years without a prior history of CVD. The primary outcome was a composite development of stroke or myocardial infarction. Statin use during follow-up was treated as a time-varying variable. We performed a multivariable time-dependent Cox regression analysis adjusting for sex, age, type of insurance, hypertension, renal disease, and use of antiplatelets and renin-angiotensin-aldosterone system inhibitors.

RESULTS

During the mean follow-up of 9.9 ± 3.7 years of follow-up, 931 T1D patients (8.5%) suffered primary outcome. Statin treatment was associated with a reduced risk of the primary outcome (adjusted hazard ratio, 0.76; 95% confidence interval 0.66-0.88; p < 0.001). Statin use led to decreased risks of ischemic stroke and myocardial infarction, but was not related to hemorrhagic stroke. We also found that the risk of cardiovascular events decreased as the cumulative exposure duration of statins increased.

CONCLUSIONS

Statin use was associated with a lower risk of cardiovascular events in T1D patients. Further prospective studies are needed to confirm the potential role of statins in prevention of CVD in patients with T1D.

Renal hemodynamic dysfunction and neuropathy in longstanding type 1 diabetes: Results from the Canadian study of longevity in type 1 diabetes

AIMS

To determine the relationship between renal hemodynamic function and neuropathy in adults with ≥50-years of type 1 diabetes (T1D) compared to nondiabetic controls.

METHODS

Glomerular filtration rate (GFR, inulin), effective renal plasma flow (ERPF, p-aminohippurate), modified Toronto Clinical Neuropathy Score (mTCNS), corneal confocal microscopy, nerve conduction, and heart rate variability (autonomic function) were measured; afferent (RA) and efferent (RE) arteriolar resistances were estimated using the Gomez equations in 74 participants with T1D and in 75 controls. Diabetic kidney disease (DKD) non-resistors were defined by eGFRMDRD < 60 ml/min/1.73 m2 or 24-h urine albumin excretion >30 mg/day. Linear regression was applied to examine the relationships between renal function (dependent variable) and neuropathy measures (independent variable), adjusted for age, sex, HbA1c, systolic blood pressure, low density lipoprotein cholesterol, and 24-h urine albumin to creatinine ratio.

RESULTS

Higher mTCNS associated with lower renal blood flow (β ± SE:-9.29 ± 4.20, p = 0.03) and greater RE (β ± SE:32.97 ± 15.43, p = 0.04) in participants with T1D, but not in controls. DKD non-resistors had a higher mTCNS and worse measures of corneal nerve morphology compared to those without DKD. Renal hemodynamic parameters did not associate with autonomic nerve function.

CONCLUSIONS

Although neurological dysfunction in the presence of diabetes may contribute to impaired renal blood flow resulting in ischemic injury in patients with T1D, early autonomic dysfunction does not appear to be associated with kidney function changes.

Statins, Enzyme CoQ10 Supplement Use, and Cognitive Functioning

OBJECTIVE

The current study assessed the effects of statin and CoQ₁₀ supplement use on changes in cognitive functioning in the Wisconsin Registry for Alzheimer's Prevention study.

METHODS

1,573 subjects were administered medical histories, the Mini-Mental State Examination (MMSE), Rey Auditory Verbal Learning Test (RAVLT), Wechsler Memory Scale, Logical Memory subtest, and the Trail Making Test, Parts A (TMT-A) and B (TMT-B) 3-4 times over 5-10 years.

RESULTS

Linear mixed models did not yield significant effects for statin or CoQ₁₀ supplement use on changes in mental status, learning and memory, psychomotor speed, and cognitive flexibility.

CONCLUSIONS

Statin and/or CoQ₁₀ supplement use was not associated with neuropsychological test performance in the Wisconsin Registry for Alzheimer's Prevention study.

Arterial stiffness in patients with type 1 diabetes and its comparison to cardiovascular risk evaluation tools

Background

Arterial stiffness is a potential biomarker for cardiovascular disease (CVD) risk in patients with type 1 diabetes (T1D). However, its relation with other CV risk evaluation tools in T1D has not been elucidated yet. This study aimed to evaluate arterial stiffness in T1D patients free from known CVD, and compare it to other CV risk evaluation tools used in T1D.

Methods

Cross-sectional study in adults with a T1D duration of at least 10 years and without established CVD. Patients were categorized in CVD risk groups based on 2019 European Society of Cardiology (ESC) guidelines, and the STENO T1D risk engine was used to estimate 10-year risk for CV events. Arterial stiffness was evaluated with carotid-femoral pulse wave velocity (cf-PWV). Coronary artery calcium (CAC) score was assessed and carotid ultrasound was performed. Ambulatory 24-h blood pressure and central hemodynamic parameters were evaluated. Data on renal function and diabetic kidney disease was retrieved.

Results

54 patients (age: 46 ± 9.5 years; T1D duration: 27 ± 8.8 years) were included. One-fourth of patients showed prematurely increased aortic stiffness based on cf-PWV (24%). Cf-PWV was significantly associated with CAC score, carotid intima-media thickness, central hemodynamic parameters and diabetic kidney disease. Based on STENO, 20 patients (37%) were at low, 20 patients (37%) at moderate, and 14 patients (26%) at high 10-year risk for CV event. Cf-PWV was strongly associated with the STENO score (r_s = + 0.81; R² = 0.566, p < 0.001), increasing with each higher STENO group (p < 0.01). However, cf-PWV was not significantly different between the two CV risk groups (high versus very high) based on ESC criteria, and ESC criteria compared to STENO classified 10 patients more as having > 10% 10-year risk for CV events (n = 44/54; 81.5% versus n = 34/54; 63%).

Conclusions

This study demonstrated that a substantial proportion of long-standing T1D patients free from known CVD show premature arterial stiffening. Cf-PWV strongly associates with the STENO risk score for future CV events and with cardiovascular imaging and function outcomes, thereby illustrating the clinical importance of arterial stiffness. The data, however, also show considerable heterogeneity in CV risk and differences in risk categorisation between the STENO tool and ESC criteria.There is a need for refinement of CV risk classification in T1D, and future studies should investigate if evaluation of arterial stiffness should be implemented in T1D clinical practice and which patients benefit the most from its assessment.

The association between physical activity time and neuropathy in longstanding type 1 diabetes: A cross-sectional analysis of the Canadian study of longevity in type 1 diabetes

AIM

Physical activity (PA) is recommended to improve glycemic control in T1D; however, the effect of PA on distal symmetric polyneuropathy (DSPN) and cardiac autonomic function in longstanding T1D is unknown.

METHODS

Data from 75 participants were collected as part of the Canadian Study of Longevity in T1D. Participants completed a physical exam, medical history, extensive complications phenotyping and reported their daily PA from the preceding 12-months. Pearson and Spearman correlations were used to assess PA time and complications variables. Linear regression was used to test associations between PA time, neurological and electrophysiological measures. Univariable regression was used to indicate the change in the given independent variables associated with a 30-min increase in PA per week.

RESULTS

Participants were 66 ± 8 years old with diabetes duration of 54 [52,58] years, HbA_1c was 7.3 ± 0.8, 65(89%) had DSPN. Weekly PA time was 156 ± 132 min, and 35(47%) reported ≧150 min/week. Participants with DSPN reported lower PA time compared to individuals without DSPN (141 ± 124 min/week vs. 258 ± 129 min/week; p = 0.015). PA time was associated with better cooling detection threshold (r = 0.24; p = 0.043), peroneal and sural amplitude (r = 0.36; p = 0.0017, r_s = 0.26; p = 0.024) and conduction velocity (r_s = 0.28; p = 0.015, r = 0.23; p = 0.050). Linear regression adjusting for age and HbA1c, showed that for each 30-min of PA there was a 0.09mv higher peroneal amplitude (p = 0.032) and 0.048 ms lower peroneal F-wave latency (p = 0.022).

CONCLUSION

In longstanding T1D, PA time is associated with superior large nerve fibre function in the lower limbs and some better measures of small nerve fibre function.

Prevalence and factors associated with lipid-lowering medications use for primary and secondary prevention of cardiovascular diseases among Malaysians: the REDISCOVER study

Background

Lipid-lowering medications (LLM) are commonly used for secondary prevention, as well as for primary prevention among patients with high global cardiovascular risk and with diabetes. This study aimed to determine the prevalence of LLM use among high-risk individuals [participants with diabetes, high Framingham general cardiovascular (FRS-CVD) score, existing cardiovascular disease (CVD)] and the factors associated with it.

Methods

This is a cross-sectional analysis from the baseline recruitment (years 2007 to 2011) of an ongoing prospective study involving 11,288 participants from 40 rural and urban communities in Malaysia. Multiple logistic regression was used to identify characteristics associated with LLM use.

Results

Majority (74.2%) of participants with CVD were not on LLM. Only 10.5% of participants with high FRS-CVD score, and 17.1% with diabetes were on LLM. Participants who were obese (OR = 1.80, 95% CI: 1.15–2.83), have diabetes (OR = 2.38, 95% CI: 1.78–3.19), have hypertension (OR = 2.87, 95% CI: 2.09–3.95), and attained tertiary education (OR = 2.25, 95% CI: 1.06–4.78) were more likely to be on LLM. Rural residents had lower odds of being on LLM (OR = 0.58, 95% CI: 0.41–0.82). In the primary prevention group, participants with high FRS-CVD score (OR = 3.81, 95% CI: 2.78–5.23) and high-income earners (OR = 1.54, 95% CI: 1.06–2.24) had higher odds of being on LLM.

Conclusions

LLM use among high CVD-risk individuals in the primary prevention group, and also among individuals with existing CVD was low. While CVD risk factors and global cardiovascular risk score were positively associated with LLM use, sociodemographic disparities were observed among the less-educated, rural residents and low-income earners. Measures are needed to ensure optimal and equitable use of LLM.

Cardiovascular disease in patients with type 1 diabetes: Early evaluation, risk factors and possible relation with cardiac autoimmunity

Cardiovascular disease now is the leading cause of mortality among patients with type 1 diabetes (T1D). The risk of death from cardiovascular events in subjects with T1D is 2-10 times higher than the general population, depending on blood glucose control. Although complications of cardiovascular disease occur in middle and old age, pathological processes begin in childhood. Some methods used to evaluate subclinical cardiovascular disease, such as carotid intima-media thickness and pulse wave velocity, can detect early cardiovascular abnormalities in adolescence. The effect of risk factors including hypertension, dyslipidemia and diabetic nephropathy on cardiovascular disease has been well studied. According to the current clinical practice recommendations from the American Diabetes Association, cardiovascular risk factors should be systematically assessed at least annually and treated as recommended. And yet, the effects of intensive insulin therapy on cardiovascular risk, as well as the mechanisms of cardiac autoimmunity require further studying. This review concentrates on the cardiovascular risk in type 1 diabetes in order to provide a comprehensive outlook of its epidemiology, early assessment, risk factors and possible relations with cardiac autoimmunity, aiming to propose promising therapeutic strategies.

Presence and Determinants of Cardiovascular Disease and Mortality in Individuals With Type 1 Diabetes of Long Duration: The FinnDiane 50 Years of Diabetes Study

OBJECTIVE

The aim of this study was to determine the incidence of cardiovascular disease (CVD) and mortality as well as their risk factors in type 1 diabetes (T1D) of >50 years' duration.

RESEARCH DESIGN AND METHODS

From 5,396 individuals included in the Finnish Diabetic Nephropathy Study (FinnDiane), 729 diagnosed in 1967 or earlier survived with T1D for >50 years. In this FinnDiane 50-year cohort, cumulative incidence of CVD events was assessed from the diagnosis of diabetes, and the excess CVD risk, compared with 12,710 matched individuals without diabetes. In addition, risk factors for different types of CVD (both nonfatal and fatal) and mortality were analyzed, and cause-specific hazard ratios were estimated during a median follow-up of 16.6 years from the baseline visit (median duration of diabetes 39 years at baseline).

RESULTS

In individuals with diabetes duration of >50 years, the 60-year cumulative incidence of CVD from the diagnosis of diabetes was 64.3% (95% CI 62.5-66.0). Compared with individuals without diabetes, the standardized incidence ratio for CVD was 7.4 (6.5-8.3); in those with normoalbuminuria, it was 4.9 (4.0-5.9). Mean HbA_1c and HbA_1c variability, dyslipidemia, BMI, kidney disease, age, and diabetes duration were the variables associated with incident CVD. In particular, HbA_1c was associated with peripheral artery disease (PAD). The standardized mortality ratio compared with the Finnish background population was 3.2 (2.8-3.7). The factors associated with mortality were diabetes duration, increased HbA_1c variability, inflammation, insulin resistance, kidney disease, and PAD.

CONCLUSIONS

Individuals with T1D of very long duration are at a high risk of CVD. In addition, throughout the lifespan, optimal glycemic control remains central to CVD and excess mortality prevention.

Discoveries from the study of longstanding type 1 diabetes

Award programmes that acknowledge the remarkable accomplishments of long-term survivors with type 1 diabetes have naturally evolved into research programmes to determine the factors associated with survivorship and resistance to chronic complications. In this review, we present an overview of the methodological sources of selection bias inherent in survivorship research (selection of those with early-onset diabetes, incidence-prevalence bias and bias from losses to follow-up in cohort studies) and the breadth and depth of literature focusing on this special study population. We focus on the learnings from the study of longstanding type 1 diabetes on discoveries about the natural history of insulin production loss and microvascular complications, and mechanisms associated with them that may in future offer therapeutic targets. We detail descriptive findings about the prevalence of preserved insulin production and resistance to complications, and the putative mechanisms associated with such resistance. To date, findings imply that the following mechanisms exist: strategies to maintain or recover beta cells and their function; activation of specific glycolytic enzymes such as pyruvate kinase M2; modification of AGE production and processing; novel mechanisms for modification of renin-angiotensin-aldosterone system activation, in particular those that may normalise afferent rather than efferent renal arteriolar resistance; and activation and modification of processes such as retinol binding and DNA damage checkpoint proteins. Among the many clinical and public health insights, research into this special study population has identified putative mechanisms that may in future serve as therapeutic targets, knowledge that likely could not have been gained without studying long-term survivors.

Statin prescription among patients with type 2 diabetes in Botswana: findings and implications

BACKGROUND

There is evidence of statin benefit among patients with diabetes regardless of cholesterol levels or prior cardiovascular disease history. Despite the evidence, there is under-prescription of statins in clinical practice. This study aimed to assess statin prescriptions and associated factors among patients with type 2 diabetes in Botswana.

METHODS

The study was a secondary data analysis of 500 randomly selected type 2 diabetes patients at a specialised diabetes clinic at Gaborone, Botswana. We assessed the proportion of statin-eligible patients who are prescribed statins and evaluated the adjusted associations between various factors and statin prescriptions.

RESULTS

Overall, 477 (95.4%) participants were eligible for a statin prescription. Clinicians prescribed statins in 217 (45.5%) of eligible participants, and only one (4.4%) ineligible participant. The probability of a statin prescription was higher in participants with high baseline low-density lipoprotein cholesterol (risk ratio [RR]: 1.49; 95%CI: 1.17-1.89), increasing duration of diabetes (RR: 1.01; 95%CI 1.00-1.03) and the presence of chronic kidney disease (RR: 1.35; 95%CI: 1.06-1.74).

CONCLUSION

A large proportion with type 2 diabetes in Gaborone is not receiving statins. Clinicians did not consider most guideline-recommended indications for statin prescriptions. The findings call for improvement in diabetes quality of care by implementing evidence-based guideline recommendations.

Adherence to lipid-lowering therapy and risk for cardiovascular disease and death in type 1 diabetes mellitus: a population-based study from the Swedish National Diabetes Register

Dyslipidemia is an important modifiable risk factor and lipid-lowering treatment (LLT) is essential to reduce the risk of cardiovascular disease (CVD). Studies in type 2 diabetes indicate that low adherence to statin therapy is a barrier to reach full protective potential, and less is known in type 1 diabetes (T1D). The aim was to assess risk of CVD by adherence and nonpersistence to LLT in T1D.  METHOD: A population-based study with a retrospective longitudinal design was conducted between 2006 and 2010, with follow-up until December 2013. In total, 6192 adult individuals with T1D, initiating LLT between 2006 and 2010, were included. Information on LLT, socioeconomic characteristics, comorbidities and cardiovascular events were collected. After 18 months, refill adherence was estimated by calculating medication possession ratio (MPR). Nonpersistence was defined as being without medicines on hand for at least 180 days. Individuals were thereafter followed until CVD, death or end of follow-up in December 2013. Cox regression analyses were performed to assess adherence level and nonpersistence of LLT as predictor of CVD. Analyses were adjusted for cardiovascular risk factors and socioeconomic status.   RESULTS: Mean MPR was 72%, 52% of the participants had an MPR above 80% and 27% discontinued LLT. There were 637 nonfatal and 58 fatal CVD events, mean follow-up 3.6 and 3.9 years, respectively. MPR above 80% was associated with reduced risk for nonfatal CVD compared with lower MPR, HR 0.78 (95% CI 0.65 to 0.93)). For fatal CVD, results indicated a negative effect of high adherence but the association did not reach statistical significance, HR 1.96 (0.96 to 4.01). Individuals discontinuing LLT had higher risk of nonfatal CVD, HR 1.43 (95% CI 1.18 to 1.73).  CONCLUSIONS/INTERPRETATION: In T1D, the risk for nonfatal CVD was lower among individuals with high adherence and higher among those discontinuing LLT within 18 months. It is important to evaluate and emphasize adherence to prescribed LLT at clinical visits to achieve treatment goals and reduce the risk of CVD.

Bone mineral density in patients with longstanding type 1 diabetes: Results from the Canadian Study of Longevity in Type 1 Diabetes

AIM

It is currently unclear if longstanding type 1 diabetes (T1D) affects bone mineral density (BMD).

METHODS

BMD measured by dual-energy X-ray absorptiometry and history of fragility fracture was determined in 75 T1D participants with ≥50 years of diabetes duration and 75 age- and sex-matched non-diabetic controls. BMD T-scores were determined for the lumbar spine (LS), total hip (TH) and femoral neck (FN).

RESULTS

T1D participants had median diabetes duration of 54 [52, 58] years, 41 (55%) were females, and mean A_1c was 7.3 ± 0.8%. T1D females had higher LS T-scores compared to female controls (-0.3 ± 1.2 vs. -1.1 ± 1.4, p = 0.014), lower FN T-scores (-1.5 ± 1.0 vs. -1.2 ± 0.9, p = 0.042) and more fragility fractures (7 (17%) vs. 1 (2%), p = 0.021). In T1D, higher A1c was associated with higher adjusted odds of fragility fracture (p = 0.006). T1D males and controls showed no difference in BMD or fractures.

CONCLUSIONS

There were no substantial differences in T-score between T1D and matched controls; however, T1D females showed higher BMD at the LS and possibly paradoxically higher fragility fractures compared to matched controls. These findings suggest that lower T-scores may not be associated with a history of fragility fracture in females with longstanding T1D and that other factors should be investigated.

HbA1c variability and long-term glycemic control are linked to diabetic retinopathy and glomerular filtration rate in patients with type 1 diabetes and multiethnic background

AIM

To evaluate the associations between HbA1c variability and long-term glycemic control with microvascular complications in type 1 diabetes (T1D) patients and multiethnic background.

METHODS

T1D adults with ≥10 years of follow-up and ≥ 2 HbA1c measurements were included. Glycemic variability was evaluated by the standard deviation (HbA1c-SD), and coefficient of variation (HbA1c-CV), and glycemic control by mean HbA1c over 10 years. Diabetic retinopathy (DR), increased urinary albumin excretion rate (UAER) and reduced glomerular filtration rate (eGFR) were diagnosed. Cardiac autonomic neuropathy (CAN) was diagnosed by cardiac reflex tests. Associations between glycemic parameters with complications were assessed by multivariate logistic regressions.

RESULTS

220 patients were included. Simultaneously adjusted for each other, mean HbA1c was independently associated with DR (OR: 2.82; 95%CI: 1.45-5.50), increased UAER (OR: 1.97; 95%CI: 1.14-3.09) and CAN (OR: 4.42; 95%CI: 1.45-13.51); whereas HbA1c-CV was independently associated with DR (OR: 8.93; 95%CI: 1.86-42.87) and reduced eGFR (OR: 7.02; 95%CI: 1.47-35.55).

CONCLUSIONS

Long-term glycemic control was associated with DR, increased UAER and CAN, while glycemic variability was additionally associated with DR and impaired renal function; suggesting that both good and stable glycemic status might be important to prevent microvascular complications in T1D patients and multiethnic background.

The relationships between markers of tubular injury and intrarenal haemodynamic function in adults with and without type 1 diabetes: Results from the Canadian Study of Longevity in Type 1 Diabetes

OBJECTIVE

Our aim was to define the relationships between plasma biomarkers of kidney injury and intrarenal haemodynamic function (glomerular filtration rate [GFR], effective renal plasma flow [ERPF], renal vascular resistance [RVR]) in adults with type 1 diabetes (T1D).

METHODS

The study sample comprised patients with longstanding T1D (duration ≥50 years), among whom 44 were diabetic kidney disease (DKD) resistors (eGFR >60 mL/min/1.73 m² and <30 mg/d urine albumin excretion) and 22 had DKD, in addition to 73 control participants. GFR_INULIN and ERPF_PAH were measured, RVR was calculated, and afferent (R_A )/efferent (R_E ) areteriolar resistances were derived from Gomez equations. Plasma neutrophil gelatinase-associated lipocalin (NGAL), β2 microglobulin (B2M), osteopontin (OPN) and uromodulin (UMOD) were measured using immunoassay kits from Meso Scale Discovery.

RESULTS

Plasma NGAL, B2M and OPN were higher and UMOD was lower in DKD patients vs DKD resistors and non-diabetic controls. In participants with T1D, plasma NGAL inversely correlated with GFR (r = -0.33; P = 0.006) and ERPF (r = -0.34; P = 0.006), and correlated positively with R_A (r = 0.26; P = 0.03) and RVR (r = 0.31; P = 0.01). In participants without T1D, NGAL and B2M inversely correlated with GFR (NGAL r = -0.18; P = 0.13 and B2M r = -0.49; P < 0.0001) and with ERPF (NGAL r = -0.19; P = 0.1 and B2M r = -0.42; P = 0.0003), and correlated positively with R_A (NGAL r = 0.19; P = 0.10 and B2M r = 0.3; P = 0.01) and with RVR (NGAL r = 0.20; P = 0.09 and B2M r = 0.34; P = 0.003). Differences were significant after adjusting for age, sex, HbA1c, SBP and LDL. There were statistical interactions between T1D status, B2M and intrarenal haemodynamic function (P < 0.05).

CONCLUSIONS

Elevated NGAL relates to intrarenal haemodynamic dysfunction in T1D, whereas elevated NGAL and B2M relate to intrarenal haemodynamic dysfunction in adults without T1D. These data may define a diabetes-specific interplay between tubular injury and intrarenal haemodynamic dysfunction.

Estimating GFR by Serum Creatinine, Cystatin C, and β2-Microglobulin in Older Adults: Results From the Canadian Study of Longevity in Type 1 Diabetes

Introduction

Glomerular filtration rate (GFR) is routinely used for clinical assessment of kidney function. However, the accuracy of estimating equations in older adults is uncertain.

Methods

In 66 adults with ≥50 years type 1 diabetes (T1D) duration and 73 nondiabetic controls from age/sex-matched subgroups (65 ± 8 years old and 77[55%] were women) we evaluated the performance of estimated GFR (eGFR) by creatinine (Modification of Diet and Renal Disease [MDRD], Chronic Kidney Disease–Epidemiology [CKD-EPI]_cr), cystatin C (CKD-EPI_cys, CKD-EPI_cr-cys), and β₂-microglobulin (β2M) compared with measured GFR by inulin clearance (mGFR). Performance was evaluated using metrics of bias (mean difference), precision (SD), and accuracy (proportion of eGFR that differed by >20% of mGFR).

Results

Mean mGFR was 104 ± 18 ml/min per 1.73 m² (range: 70–154 ml/min per 1.73 m²) and was not different between T1D and controls (103 ± 17 vs. 105 ± 19 ml/min per 1.73 m², P = 0.39). All equations significantly underestimated mGFR (bias: −15 to −30 ml/min per 1.73 m², P < 0.001 for all comparisons) except for β2M, which had bias of 1.9 ml/min per 1.73 m² (P = 0.61). Bias was greatest in cystatin C–based equations. Precision was lowest for β2M (SD: 43.5 ml/min per 1.73 m², P < 0.001 for each comparison). Accuracy was lowest for CKD-EPI_cysC (69.1%, P < 0.001 for each comparison). Cystatin C–based equations demonstrated greater bias and lower accuracy in older age subgroups (<60, 60–69, ≥70 years). All equations demonstrated greater bias across higher ranges of mGFR (60–89, 90–119, ≥120 ml/min per 1.73 m²). Results were similar between T1D and controls except that β2M had lower performance in T1D.

Conclusion

Better estimates of GFR in older adults are needed for research and clinical practice, as this subgroup of the population has an amplified risk for the development of chronic kidney disease (CKD) that requires accurate GFR estimation methods.

Retinopathy and RAAS Activation: Results From the Canadian Study of Longevity in Type 1 Diabetes

OBJECTIVE

The importance of renin-angiotensin-aldosterone system (RAAS) activation in retinopathy for long-standing diabetes is not well understood. We determined retinopathy stage and evaluated associations with other vascular complications before and after physiological RAAS activation in adults with long-standing (≥50 years duration) type 1 diabetes.

RESEARCH DESIGN AND METHODS

Participants underwent retinal examination by digital funduscopic photography and optical coherence tomography and were classified as having nonproliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR), or no diabetic retinopathy (NDR) with or without diabetic macular edema (DME). Neuropathy was measured by clinical neuropathy examination scores, electrophysiologically, and by corneal confocal microscopy. Renal function was measured by inulin and para-aminohippurate clearance methods. Arterial stiffness was measured by applanation tonometry. Renal function, blood pressure, and arterial stiffness were measured before and after RAAS activation with angiotensin II (ANGII). Associations were determined using linear regression.

RESULTS

Twelve (16%) of the 75 participants had NDR, 24 (32%) had NPDR, and 39 (52%) had PDR. A low overall prevalence of DME (4%) was observed. Those with PDR had worse nerve function and reduced corneal nerve density, were more likely to have macrovascular disease, and had increased arterial stiffness in response to ANGII compared with those with NPDR or NDR. Prevalence of kidney disease or renal hemodynamic function did not differ by retinopathy status.

CONCLUSIONS

PDR was associated with neuropathy severity and cardiovascular and peripheral vascular disease. In those with PDR, RAAS activation may be linked to vascular stiffening, an effect that persists in long-standing type 1 diabetes.

Effect of statins on fasting glucose in non-diabetic individuals: nationwide population-based health examination in Korea

BACKGROUND

Increasing evidence suggest that statin therapy has a diabetogenic effect. Individual types of statin may have a different effect on glucose metabolism. Using the repeated nationwide population-based health screening data in Korea, we investigated the longitudinal changes in fasting glucose level of non-diabetic individuals by use of statins.

METHODS

From the National Health Screening Cohort, we included 379,865 non-diabetic individuals who had ≥ 2 health screening examinations with fasting blood glucose level measured in 2002-2013. Using the prescription records of statins in the database, we calculated the proportion of days covered (PDC) and average number of defined daily doses per day (anDDD) by statins. We constructed multivariate linear mixed models to evaluate the effects of statins on the changes in fasting glucose (Δglu).

RESULTS

High PDC by statins had a significant positive effect on Δglu (coefficient for PDC 0.093 mmol/L, standard error 0.007, p < 0.001). anDDD by statins was also positively associated with Δglu (coefficient for anDDD 0.119 mmol/L, standard error 0.009, p < 0.001). Unlike statins, the PDC by fibrate and ezetimibe were not significantly associated with Δglu. There was no significant interaction effect on Δglu between time interval and statin. Considering individual types of statins, use of atorvastatin, rosuvastatin, pitavastatin, and simvastatin were significantly associated with increase of Δglu. Pravastatin, lovastatin, and fluvastatin were also positively associated with Δglu, but were not statistically significant.

CONCLUSIONS

More adherent and intensive use of statins was significantly associated with an increase in fasting glucose of non-diabetic individuals. In subgroup analysis of individual statins, use of atorvastatin, rosuvastatin, pitavastatin and simvastatin had significant association with increase in fasting glucose. Pravastatin, lovastatin, and fluvastatin had non-significant trend toward an increased fasting glucose. Our findings suggest the medication class effect of statins inducing hyperglycemia.

Atherosclerosis and Microvascular Complications: Results From the Canadian Study of Longevity in Type 1 Diabetes

OBJECTIVE

Type 1 diabetes carries a significant risk for cardiovascular mortality, but it is unclear how atherosclerosis associates with microvascular complications. We aimed to determine the relationships between atherosclerotic burden and neuropathy, retinopathy, and diabetic kidney disease (DKD) in adults with a ≥50-year history of type 1 diabetes.

RESEARCH DESIGN AND METHODS

Adults with type 1 diabetes (n = 69) underwent coronary artery calcification (CAC) volume scoring by wide-volume computerized tomography. Microvascular complications were graded as follows: neuropathy by clinical assessment, electrophysiology, vibration and cooling detection thresholds, heart rate variability, and corneal confocal microscopy; retinopathy by ultra-wide-field retinal imaging; and DKD by renal hemodynamic function measured by inulin and para-aminohippurate clearance at baseline and after intravenous infusion of angiotensin II. The cohort was dichotomized to high (≥300 Agatston units [AU]) or low (<300 AU) CAC and was stratified by diabetes status. A comparator group without diabetes (n = 73) matched for age and sex also underwent all study procedures except for retinal imaging.

RESULTS

CAC scores were higher in participants with type 1 diabetes (median Agatston score 1,000 [interquartile range = 222, 2,373] AU vs. 1 [0.75] AU in comparators, P < 0.001). In participants with type 1 diabetes, high CAC scores associated with markers of neuropathy and retinopathy, but not with DKD, or renal hemodynamic function at baseline or in response to angiotensin II.

CONCLUSIONS

The presence of high CAC in adults with longstanding type 1 diabetes was associated with large nerve fiber neuropathy and retinopathy but not with renal hemodynamic function, suggesting that neuropathy, retinopathy, and macrovascular calcification share common risk factors.

Validity of a point-of-care nerve conduction device for polyneuropathy identification in older adults with diabetes: Results from the Canadian Study of Longevity in Type 1 Diabetes

Objective

Point-of-care nerve conduction devices (POCD) have been studied in younger patients and may facilitate screening for polyneuropathy in non-specialized clinical settings. However, performance may be impaired with advanced age owing to age-related changes in nerve conduction. We aimed to evaluate the validity of a POCD as a proxy for standard nerve conduction studies (NCS) in older adults with type 1 diabetes (T1D).

Methods

Sural nerve amplitude potential (AMP) and sural nerve conduction velocity (CV) was measured in 68 participants with ≥ 50 years T1D duration and 71 controls (from age/sex-matched subgroups) using POCD and NCS protocols. Agreement was determined by the Bland-Altman method, and validity was determined by receiver operating characteristic curves.

Results

T1D were 53% female, aged 66±8yr and had diabetes duration 54yr[52,58]. Controls were 56%(p = 0.69) female and aged 65±8yr(p = 0.36). Mean AMP_POCD and CV_POCD for the 139 participants was 7.4±5.8μV and 45.7±11.2m/s and mean AMP_NCS and CV_NCS was 7.2±6.1μV and 43.3±8.3m/s. Mean difference of AMP_POCD−AMP_NCS was 0.3±3.8μV and was 2.3±8.5m/s for CV_POCD−CV_NCS. A AMP_POCD of ≤6μV had 80% sensitivity and 80% specificity for identifying abnormal AMP_NCS, while a CV_POCD of ≤44m/s had 81% sensitivity and 82% specificity to identify abnormal CV_NCS. Abnormality in AMP_POCD or CV_POCD was associated with 87% sensitivity, while abnormality in both measures was associated with 97% specificity for polyneuropathy identification.

Conclusions

The POCD has strong agreement and diagnostic accuracy for identification of polyneuropathy in a high-risk subgroup and thus may represent a sufficiently accurate and rapid test for routinely detecting those with electrophysiological dysfunction.

Diabetic Retinopathy and Dementia in Type 1 Diabetes

OBJECTIVE

Retinopathy impacts over one-third of those with diabetes mellitus and is associated with impaired cognitive performance and cerebrovascular lesions in middle-aged adults with type 1 diabetes. However, the association between diabetic retinopathy (DR) and risk of dementia in type 1 diabetes is unknown. We investigated the association between DR and incident dementia in a large, elderly population with type 1 diabetes.

METHODS

A cohort of 3742 patients with type 1 diabetes aged 50 years and above was followed from January 1, 1996 to September 30, 2015 for incident dementia. DR diagnoses were identified from electronic medical records. Age as timescale Cox proportional hazard models evaluated associations between time-updated DR and dementia risk. Models were adjusted for demographics, severe glycemic events, glycosylated hemoglobin, and vascular comorbidities.

RESULTS

Among 3742 patients with type 1 diabetes (47% female, 21% nonwhite), 182 (5%) were diagnosed with dementia during a mean follow-up of 6.2 years. No significant association was found between DR and incident dementia in the main analyses [adjusted Hazard Ratio=1.12; 95% confidence interval, 0.82-1.54), nor among subgroup restricted to those aged 60 years and above or 70 years and above.

CONCLUSIONS

DR was not associated with risk of dementia, suggesting that pathophysiological processes underlying dementia may be different in type 1 versus type 2 diabetes.

Diabetes Care Disparities in Long-standing Type 1 Diabetes in Canada and the U.S.: A Cross-sectional Comparison

OBJECTIVE

To assess national differences in diabetes care and quality of life (QOL) between individuals with long-standing type 1 diabetes (≥50 years) in Canada and the U.S.

RESEARCH DESIGN AND METHODS

Cross-sectional data from identical surveys administered in the Canadian Study of Longevity in Diabetes and the Joslin Medalist Study, collected in 2013-2016 and 2005-2011, respectively, were compared. Laboratory values and ophthalmic examination were completed by clinical care physicians for Canadians and the Joslin Clinic for Americans. Univariate comparisons and multivariable regression for HbA_1c, QOL, insulin pump use, and coronary artery disease (CAD) were performed. Nephropathy, CAD, and peripheral arterial disease (PAD) were self-reported; neuropathy was defined by a Michigan Neuropathy Screening Instrument (Questionnaire component) score ≥3, and proliferative retinopathy was documented from ophthalmic examination. QOL was self-reported on an ordinal scale.

RESULTS

Three hundred sixty-one Canadians and 668 Americans had similar ages (mean 65.78 years [SD 8.67] vs. 66.38 years [7.66], P = 0.27) and durations of diabetes (median 53.00 years [interquartile range 51.00, 58.00] vs. 53.00 years [51.00, 57.00], P = 0.51). Canadians had higher HbA_1c (mean 7.53% [SD 1.03] [59 mmol/mol] vs. 7.22% [0.98] [55 mmol/mol], P < 0.0001), lower QOL (36.9% vs. 48.7% with "excellent" QOL, P = 0.0002), and less CAD (29.7% vs. 41.2%, P = 0.0003) and insulin pump use (43.3% vs. 55.6%, P = 0.0002). Other complication rates were similar. Residual differences for Canadians compared with Americans remained after adjustment for age, sex, CAD, PAD, education, and relevant a priori selected variables: 0.28% higher HbA_1c (P = 0.0004); and odds ratios of 0.68 (95% CI 0.51, 0.90), 0.46 (0.31, 0.68), and 0.71 (0.52, 0.96) for higher QOL, CAD, and insulin pump use, respectively.

CONCLUSIONS

Although Canadians and Americans have similar rates of complications other than CAD, further research is required to understand why Canadians have higher HbA_1c levels, lower QOL, and less insulin pump use.

Longitudinal trends and predictors of statin use among patients with diabetes

AIM

Statins reduce morbidity and mortality among patients with diabetes, but their use remains suboptimal. Understanding trends in statin use may inform strategies for improvement.

METHODS

We enrolled a national, retrospective cohort of 899,664 veterans aged≥40years with diabetes in 2003. We followed them through 2011, dividing the nine-year follow-up into 90-day periods. For each period, we determined statin use, defined as possession of ≥30-day supply. We examine factors associated with statin uptake among baseline non-users with a multivariate model.

RESULTS

Baseline prevalence of statin use was 43%, increased by 1.8% per period (p for trend<0.001), and reached a maximum of ~59%. Statin use among non-Hispanic racial/ethnic minorities lagged behind their white counterparts. Among baseline non-users, statin use was 9% after Year 1 and reached 36% by Year 9. Factors associated with statin uptake included use of hypoglycemic agents, HbA1c between 7 and 8.9% (53-74mmol/mol), hypertension, heart failure, peripheral vascular disease, and Hispanic ethnicity.

CONCLUSION

Statin use is slowly increasing among patients with diabetes, and at varying rates within subgroups of this population. Policies that prioritize these subgroups for statin promotion may help guide future, intervention-based research to increase compliance with current guidelines.

Neuropathy and presence of emotional distress and depression in longstanding diabetes: Results from the Canadian study of longevity in type 1 diabetes

AIM

To determine the association of neuropathy and other complications with emotional distress and depression among patients with longstanding type 1 diabetes (T1DM).

METHODS

Canadians with ≥50years of T1DM completed a questionnaire including assessment of distress and depression by the Problem Areas in Diabetes Scale (PAID) and Geriatric Depression Scale (GDS), respectively. Complications were determined using the Michigan Neuropathy Screening Instrument (Questionnaire Component), fundoscopy reports, renal function tests, and self-reported peripheral-(PVD) and cardiovascular (CVD) disease. Associations were analyzed by Poisson regression.

RESULTS

Among 323 participants, 137 (42.4%) had neuropathy, 113 (36.5%) nephropathy, 207 (69.5%) retinopathy, 95 (29.4%) CVD, and 31 (9.8%) PVD. The neuropathy subgroup had higher prevalence of distress (13 (9.5%) vs. 6 (3.3%), p=0.029) and depression (34 (24.9%) vs. 12 (6.5%), p<0.001). Adjusting for diabetes complications, neuropathy was associated with higher PAID (adjusted RR 1.44 (95% CI 1.14-1.82), p=0.003) and GDS scores (adjusted RR1.57 (1.18-2.11), p=0.002). Independent of potential confounders, neuropathy remained associated with higher PAID (adjusted RR 1.39 (1.10-1.76), p=0.006) and GDS scores (adjusted RR 1.37 (1.03-1.83), p=0.032). Associations with neuropathy were not fully explained by neuropathic pain.

CONCLUSION

Compared to other complications, neuropathy had the greatest association with distress and depression in longstanding T1DM, independent of pain. Strategies beyond pain management are needed to improve quality of life in diabetic neuropathy.

Prevalence of Insulin Pump Therapy and Its Association with Measures of Glycemic Control: Results from the Canadian Study of Longevity in Type 1 Diabetes

OBJECTIVE

We aimed to determine cross-sectional insulin pump prevalence and factors associated with measures of glycemic control as a secondary analysis in a long-standing type 1 diabetes mellitus (T1DM) national cohort.

RESEARCH DESIGN AND METHODS

Canadian participants with ≥50 years of T1DM (n = 305) were administered a comprehensive mail-based questionnaire including acquisition of contemporaneous laboratory results. Factors associated with pump use, glycosylated hemoglobin (HbA1c), and hypoglycemia were analyzed by regression.

RESULTS

The 305 participants had a median age of 65 [interquartile range, 59, 71] years, median diabetes duration of 54 [51, 59] years, and mean HbA1c level of 7.5 ± 1.1%. Prevalence of pump use was 44% (133/305), with median duration of use 8 [4, 13] years. Compared with the non-pump subgroup, the pump subgroup had numerically lower but similar HbA1c levels (7.4 ± 0.9% vs. 7.6 ± 1.2%; P = 0.22) and reported greater numbers of minor hypoglycemia events (6.5 vs. 5.1 events/patient·month; P = 0.004) and fewer severe hypoglycemia events (0.5 vs. 1.3 events/patient·year; P = 0.02) in the past year. More frequent daily glucose tests and more frequent minor hypoglycemia events-but not pump therapy or its prescription parameters-were independently associated with lower HbA1c level in multivariable regression. However, use of insulin pump and habitual use of continuous glucose monitoring (≥1 week/month) were each independently associated with lower risk of severe hypoglycemia (risk ratio = 0.50 [P < 0.0001] and 0.30 [P = 0.001], respectively).

CONCLUSIONS

Insulin pump and continuous glucose monitoring technologies were associated with lower risk of severe hypoglycemia, while frequent daily glucose testing was associated with lower HbA1c level. These findings imply that basic self-management skill and technology play complementary roles in glycemic control among older adults with long-standing T1DM.