Association between glucose variation and lower extremity amputation incidence in individuals with type 2 diabetes: a nationwide retrospective cohort study

Visit to Visit Hemoglobin A1c Variation and Long-term Risk of Major Adverse Limb Events in Patients With Type 2 Diabetes

CONTEXT

Glycemic variation had been demonstrated to be associated with several complications of diabetes.

OBJECTIVE

Investigation of the association between visit to visit hemoglobin A1c (HbA1c) variation and the long-term risk of major adverse limb events (MALEs).

METHODS

Retrospective database study. Average real variability was used to represent glycemic variations with all the HbA1c measurements during the 4 following years after the initial diagnosis of type 2 diabetes. Participants were followed from the beginning of the fifth year until death or the end of the follow-up. The association between HbA1c variations and MALEs was evaluated after adjusting for mean HbA1c and baseline characteristics. Included were 56 872 patients at the referral center with a first diagnosis of type 2 diabetes, no lower extremity arterial disease, and at least 1 HbA1c measurement in each of the 4 following years were identified from a multicenter database. The main outcome measure was incidence of a MALE, which was defined as the composite of revascularization, foot ulcers, and lower limb amputations.

RESULTS

The average number of HbA1c measurements was 12.6. The mean follow-up time was 6.1 years. The cumulative incidence of MALEs was 9.25 per 1000 person-years. Visit to visit HbA1c variations were significantly associated with MALEs and lower limb amputation after multivariate adjustment. People in the highest quartile of variations had increased risks for MALEs (HR 1.25, 95% CI 1.10-1.41) and lower limb amputation (HR 3.05, 95% CI 1.97-4.74).

CONCLUSION

HbA1c variation was independently associated with a long-term risk of MALEs and lower limb amputations in patients with type 2 diabetes.

Machine learning based study of longitudinal HbA1c trends and their association with all-cause mortality: Analyses from a National Diabetes Registry

OBJECTIVE

The association of long-term HbA1c variability with mortality has been previously suggested. However, the significance of HbA1c variability and trends in different age and HbA1c categories is unclear.

RESEARCH DESIGN AND METHODS

Data on patients with diabetes listed in the Israeli National Diabetes Registry during years 2012-2016 (observation period) were collected. Patients with >4 HbA1c measurements, type 1 diabetes, eGFR < 30mg/ml/min, persistent HbA1c < 6% or malignancy were excluded. Utilizing machine learning methods, patients were classified into clusters according to their HbA1c trend (increasing, stable, decreasing). Mortality risk during 2017-2019 was calculated in subgroups defined by age (35-54, 55-69, 70-89 years) and last HbA1c (≤7% and >7%) at end of observation period. Models were adjusted for demographic, clinical and laboratory measurements including HbA1c, standard deviation (SD) of HbA1c and HbA1c trend.

RESULTS

This historical cohort study included 293,314 patients. Increased HbA1c variability (high SD) during the observation period was an independent predictor of mortality in patients aged more than 55 years (p < 0.01). The HbA1c trend was another independent predictor of mortality. Patients with a decreasing versus stable HbA1c trend had a greater mortality risk; this association persisted in all age groups in patients with HbA1c > 7% at the end of the observation period (p = 0.02 in age 35-54; p < 0.01 in aged >55). Patients with an increasing versus stable HbA1c trend had a greater mortality risk only in the elderly group (>70), yet in both HbA1c categories (p < 0.01).

CONCLUSIONS

HbA1c variability and trend are important determinants of mortality risk and should be considered when adjusting glycaemic targets.

A nationwide cohort investigation on pay-for-performance and major adverse limb events in patients with diabetes

A retrospective cohort study was conducted using claims data from Taiwan's National Health Insurance program to assess the effect of diabetic pay-for-performance (P4P) program on major adverse limb events (MALE) and major adverse cardiovascular events (MACE) in patients with type 2 diabetes mellitus (T2DM). This study included patients with T2DM who had completed or not completed a 1-year P4P program from 2002 to 2013. Propensity-score matching was used to balance the baseline characteristics between groups. The Cox proportional-hazard model and Fine and Gray subdistribution hazard model were used to examine the association between P4P and the risks of MALE, MACE, systemic thromboembolism (ST), heart failure (HF) hospitalization, and all-cause mortality. Patients who underwent the P4P program had a significantly decreased incidence of MALE (2.0% vs. 2.6%, subdistribution hazard ratio [SHR] 0.73, 95% CI 0.71-0.76). Regarding the individual components, the P4P group demonstrated lower risks for foot ulcer (1.1% vs 1.3%, SHR 0.80, 95% CI 0.77-0.84), gangrene (0.57% vs 0.93%, SHR 0.59, 95% CI 0.56-0.63), percutaneous transluminal angioplasty (0.61% vs 0.79%, SHR 0.72, 95% CI 0.68-0.77), and amputation (0.46% vs 0.75%, SHR 0.58, 95% CI 0.55-0.62). In addition, the risks of MACE, ST, HF hospitalization, and all-cause mortality were remarkably lower in the P4P group. The P4P program might significantly reduce critical events of MALE, MACE, ST, HF, and mortality in the diabetic population.

Visit-to-visit variability of clinical risk markers in relation to long-term complications in type 1 diabetes

BACKGROUND

Clinical characteristics such as HbA_1c , systolic blood pressure (SBP), albuminuria and estimated glomerular filtration rate (eGFR) are important when treating type 1 diabetes. We investigated the variability in these measures as risk markers for micro- and macrovascular complications.

METHODS

This prospective study included 1062 individuals with type 1 diabetes. Visit-to-visit variability of HbA_1c , SBP, albuminuria and eGFR was calculated as the SD of the residuals in individual linear regression models using all available measures in a specified period of 3 years (VV). Endpoints included were as follows: cardiovascular events (CVE) defined as myocardial infarction, non-fatal stroke, or coronary or peripheral arterial intervention; end-stage kidney disease (ESKD) defined as eGFR <15 ml/min/1.73 m² , chronic dialysis or kidney transplantation; eGFR decline ≥30%; and mortality. Adjustment included age, sex, cholesterol, HbA_1c , SBP, body mass index, smoking, albuminuria, eGFR, and mean, intercept, slope of respective exposure variables and regression models.

RESULTS

SBP VV was significantly associated with CVE (adjusted hazard ratio per 50% increase, (CI 95%); p: 1.21 [1.05-1.39]; p = 0.008), ESKD (1.51 [1.16-1.96]; p = 0.002) and mortality (1.25 [1.09-1.44]; p = 0.002). HbA_1c VV was significantly associated with mortality (1.51 [1.30-1.75]; p < 0.001); albuminuria VV with eGFR decline (1.14 [1.08-1.20]; p = 0.024) and ESKD (1.14 [1.02-1.27]; p < 0.001), but neither CVE nor mortality. Adjusted eGFR VV was not associated with endpoints.

CONCLUSION

In type 1 diabetes, higher variability of basic clinical risk markers adds important risk stratification information for the development of micro- and macrovascular complications.

Risk of idiopathic peripheral neuropathy in end-stage renal disease: A population-based cohort study

BACKGROUND

Whether patients with end-stage renal disease (ESRD) have a higher risk of idiopathic polyneuropathy (IPN) than those without ESRD remains unclear. We hypothesised that carpal tunnel syndrome (CTS) is a prodrome of IPN in patients with ESRD.

METHODS

Data were collected from the Taiwan National Health Insurance research database (NHIRD) for the 2000-2011 period. Two matching strategies, age- and sex-matching and propensity matching, were used, which yielded 2596 age- and sex-matched patients with ESRD and 2210 propensity-matched patients with ESRD. The comparison cohort was chosen in a 1:4 ratio for the age- and sex-matched method and in a 1:1 ratio for the propensity-matching method. The primary outcome was the incidence of IPN. Cox proportional hazards modelling was used.

RESULTS

In the age- and sex-matched cohort, the IPN incidence was 7.64 and 2.88 per 1000 person-years for the ESRD and controls cohorts, respectively. After we adjusted for age, sex, comorbidities and medications relative to controls, having ESRD was significantly associated with increased risk of IPN (hazard ratio [HR] = 2.45, 95% confidence interval [CI] = 1.76-3.41). Competing risk of death as sensitivity analysis revealed that having ESRD with CTS was still associated with higher risk of IPN than having CTS without ESRD (HR = 2.85, 95% CI = 1.87-4.34).

CONCLUSION

Patients with ESRD with CTS had higher incidences of idiopathic peripheral neuropathy than those without ESRD with CTS.

Self-Care in Type 2 Diabetes Patients with Urgency Lower Limb Amputation: The Influence of Sex, Marital Status and Previous Amputations

AIM

Lower limb amputation (LLA) is a severe consequence of type 2 diabetes mellitus (T2DM), and can affect up to 1% of T2DM patients, leading to an increased risk of premature mortality. Among the factors to predict LLA, it has been highlighted sex, marital status, and previous amputation. However, there is a lack of information about the association between these predictive factors, self-care, and urgency LLA in T2DM patients.

PURPOSE

To verify the behavior of self-care and to relate it with the predictive factors (sex, marital status, and previous amputation) in urgency LLA T2DM patients.

PATIENTS AND METHODS

Non-interventional study, with 106 T2DM patients who were in the postoperative period of urgency LLA caused by complications resulting from T2DM. A structured questionnaire was used for sociodemographic and clinical characterization of the sample as well as the Summary of Diabetes Self-Care Activities (SDSCA) tool. It was used the Wilcoxon, Friedman, and Mann-Whitney tests (median, nonparametric populations) to assess the significance of the differences between groups (sex, marital status, and previous amputation), also Spearman correlation coefficient to assess the association between the data (comparison between diagnostic time, sex, previous amputation, ethnicity and systolic arterial hypertension) and a logistic regression analysis considering the item SDSCA related to sex, age and marital status (with partner).

RESULTS

Significant differences (p<0.05) in the questions "Specific Food" and "Foot care" were found when the participants were grouped by sex. In the relation to marital status, significant differences (p<0.05) were observed for the question "Specific Food". No differences were found between groups with or without previous amputation.

CONCLUSION

By SDSCA tool, we were able to report that T2DM patients submitted to urgency LLA presented differences in self-care, particularly for sex and marital status.

Age- and sex-specific incidence of non-traumatic lower limb amputation in patients with type 2 diabetes mellitus in a U.S. claims database

AIM

To estimate age- and sex-specific incidence rates (IRs) of non-traumatic lower limb amputations (LLA) in patients with type 2 diabetes mellitus (T2DM) using a claims database from the United States (US).

METHODS

Patients with T2DM 18 years and older were identified using the Truven Health MarketScan database from January 1, 2007 to September 30, 2018. The overall and age- and sex-specific IRs of all non-traumatic LLA, minor LLA (amputation at or below the ankle), and major LLA (amputation above ankle) were calculated.

RESULTS

Among the 6,117,981 patients with T2DM, 14,627 LLA events occurred (minor LLA; 72.8%; major LLA: 27.2%). The IRs (95% CI) of all LLA, minor LLA, and major LLA per 1000 person-years or PY were 0.86 (0.85, 0.88), 0.63 (0.62, 0.64), and 0.23 (0.23, 0.24), respectively. The IR (95% CI) of all LLA per 1000 PY in males was higher compared to females [1.24 (1.22, 1.26) vs. 0.46 (0.45, 0.48)]. The incidence of all LLA increased with an increasing age (highest IR in age-group of ≥80 years).

CONCLUSIONS

This study identified males and older patients with T2DM at higher risk of developing LLA in the US, warranting further exploration of risk factors of LLA in these subgroups.