Outcomes after surgery in patients with diabetes who used metformin: a retrospective cohort study based on a real-world database

Metformin Use in Type 2 Diabetics and Delirium After Noncardiac Surgery: A Retrospective Cohort Analysis

INTRODUCTION

The cause of postoperative delirium is unknown, but it is thought to result at least in part from inflammation. Metformin, besides its hypoglycemic properties, demonstrates anti-inflammatory effects systemically and in the brain. We tested the primary hypothesis that chronic metformin use in adults with type 2 diabetes is associated with less delirium during the first 5 days after major noncardiac surgery. Secondary outcomes were a composite of serious complications (myocardial infarction, cardiac arrest, stage 2-3 acute kidney injury [AKI], and mortality) and time to discharge alive.

METHODS

We considered adults with type 2 diabetes who did or did not routinely use metformin daily and had noncardiac surgery. Delirium was assessed by Confusion Assessment Method for Intensive Care Unit (CAM-ICU) or brief Confusion Assessment Method (bCAM) for 5 postoperative days. Postoperative AKI was defined by Kidney Disease Improving Global Guidelines. Logistic regression and generalized estimating equation models accounted for within-patient correlation across multiple surgeries and explored the association between metformin use and postoperative delirium and complications. Inverse propensity score weighting and propensity score calibration (PSC) adjusted for confounding variables.

RESULTS

No significant difference was observed in the incidence of postoperative delirium between the 2 groups, with 260 of 4744 cases (5.5%) among metformin users and 502 of 5918 cases (8.5%) cases in nonmetformin users, for an odds ratio of 0.88 (95% confidence interval [CI], 0.73-1.05; P = .155), number-needed-to-expose = 118 patients. Similarly, there were fewer composite complications in metformin users (3.3%) than in nonusers (11.7%); However, the common-effect odds ratio of 0.67 was not statistically significant (97.5% CI, 0.39-1.17; P = .106). Discharge from the hospital was significantly faster in patients who took metformin (3 [interquartile range, IQR, 1-5] days for metformin users and 3 [IQR, 2-6] days for nonmetformin users), with a hazard ratio of 1.07 for early discharge, and tight CIs (1.01-1.13).

CONCLUSIONS

Chronic metformin use was associated with slightly and nonsignificantly less delirium. However, patients who used metformin had clinically meaningfully fewer major complications, mostly stage 2 to 3 kidney injury. While not statistically significant, the reduction was substantial and warrants further investigation because there is currently no effective preventive measure for perioperative renal injury. Benefit would be especially meaningful if it could be produced by acute perioperative treatment. Finally, metformin was associated with faster hospital discharge, although not by a clinically meaningful amount.

Prevalence and clinical relevance of liver dysfunction after thoracic surgery: a retrospective study

Postoperative elevation of serum aminotransferase or alkaline phosphatase levels after liver and heart surgeries has been widely reported. The prevalence and clinical significance of hypertransaminasemia/liver dysfunction after thoracic surgery remains largely unknown. Significant differences in surgical procedures between thoracic and extra-thoracic surgeries may suggest different risks of liver dysfunction. We retrospectively analyzed data from 224 consecutive patients who underwent thoracic surgery. Liver function tests were recorded the day before surgery, 12 h, 1 day, 5, and 10 days after the surgical procedure. Patients were studied to identify the frequency of hypertransaminasemia and/or hyperbilirubinemia and/or increase of INR levels. 37,5% of patients showed an increase in serum alanine aminotransferase (ALT) level after thoracic surgery, whereas an increase in gamma glutamyl transferase (GGT) serum levels of any grade was observed in 53,6% of patients. Approximately 83% of patients who experienced an increase in the serum GGT or ALT levels showed a grade 1 or 2 change. Operative time was associated with hypertransaminasemia in the univariate and multivariate analyses, whereas the use of metformin was associated with a lower risk of ALT increase.

Complications of degenerative lumbar spondylolisthesis and stenosis surgery in patients over 80 s: comparative study with over 60 s and 70 s. Experience with 678 cases

Purpose

Degenerative spondylolisthesis (DS) is a debilitating condition that carries a high economic burden. As the global population ages, the number of patients over 80 years old demanding spinal fusion is constantly rising. Therefore, neurosurgeons often face the important decision as to whether to perform surgery or not in this age group, commonly perceived at high risk for complications.

Methods

Six hundred seventy-eight elder patients, who underwent posterolateral lumbar fusion for DS (performed in three different centers) from 2012 to 2020, were screened for medical, early and late surgical complications and for the presence of potential preoperative risk factors. Patients were divided in three categories based on their age: (1) 60–69 years, (2) 70–79 years, (3) 80 and over. Multiple logistic regression was used to determine the predictive power of age and of other risk factors (i.e., ASA score; BMI; sex; presence or absence of insulin-dependent and -independent diabetes, use of anticoagulants, use of antiaggregants and osteoporosis) for the development of postoperative complications.

Results

In univariate analysis, age was significantly and positively correlated with medical complications. However, when controls for other risk factors were added in the regressions, age never reached significance, with the only noticeable exception of cerebrovascular accidents. ASA score and BMI were the two risk factors that significantly correlated with the higher numbers of complication rates (especially medical).

Conclusion

Patients of different age but with comparable preoperative risk factors share similar postoperative morbidity rates. When considering octogenarians for lumbar arthrodesis, the importance of biological age overrides that of chronological.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00701-022-05118-9.

Risk of acute atherosclerotic cardiovascular disease in patients with acute and chronic pancreatitis

The association between pancreatitis and acute myocardial infarction or stroke remains incompletely understood. This study aimed to evaluate the long-term risk of acute atherosclerotic cardiovascular disease (ASCVD) in people with acute and chronic pancreatitis. Using research database of Taiwan's National Health Insurance, we identified 2678 patients aged ≥ 20 years with newly diagnosed pancreatitis in 2000–2008. A cohort of 10,825 adults without pancreatitis was selected for comparison, with matching by age and sex. Both cohorts were followed from 2000 to the end of 2013, and incident acute ASCVD was identified during the follow-up period. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of acute ASCVD associated with pancreatitis were calculated. Compared with the comparison cohort, the adjusted HR of acute ASCVD were 1.76 (95% CI 1.47–2.12) and 3.42 (95% CI 1.69–6.94) for people with acute pancreatitis and chronic pancreatitis, respectively. A history of alcohol-related illness (HR 9.49, 95% CI 3.78–23.8), liver cirrhosis (HR 7.31, 95% CI 1.81–29.5), and diabetes (HR 6.89, 95% CI 2.18–21.8) may worsen the risk of acute ASCVD in patients with chronic pancreatitis. Compared with people had no pancreatitis, patients with acute pancreatitis who had alcohol-related illness (HR 4.66, 95% CI 3.24–6.70), liver cirrhosis (HR 4.44, 95% CI 3.05–6.47), and diabetes (HR 2.61, 95% CI 2.03–3.36) were at increased risk of acute ASCVD. However, the cumulative use of metformin was associated with a reduced risk of acute ASCVD in the acute pancreatitis cohort (HR 0.30, 95% CI 0.17–0.50). Compared with the control group, patients with acute or chronic pancreatitis were more likely to have an increased risk of acute ASCVD, while the use of metformin reduced the risk of acute ASCVD. Our findings warrant a survey and education on acute ASCVD for patients with acute and chronic pancreatitis.

Risk and outcomes of diabetes in patients with epilepsy

The risk and outcomes of diabetes in patients with epilepsy remains unclear. We evaluated these risks using an epilepsy cohort analysis and a diabetes admission analysis. In the epilepsy cohort analysis, we identified 2854 patients with newly diagnosed epilepsy in 2000–2008 from the research data of National Health Insurance in Taiwan. Using Propensity-score matching by sociodemographic factors and medical conditions, we selected 22,832 people without epilepsy as a non-exposed cohort for comparison. Follow-up events of diabetes from January 1, 2000 until December 31, 2013 were ascertained from medical claims. The adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of diabetes associated with epilepsy were calculated using multiple Cox proportional hazard models. In the diabetes admission analysis, we identified 92,438 hospitalized diabetes patients, 930 of whom had a history of epilepsy. Adjusted odds ratios (ORs) and 95% CIs of adverse events after diabetes associated with previous epilepsy were calculated using multiple logistic regressions. The adjusted HR of diabetes in the cohort with epilepsy was 1.31 (95% CI 1.14–1.50) compared to the non-epilepsy cohort. Previous epilepsy was associated with post-diabetes adverse events, such as pneumonia (OR 1.68, 95% CI 1.37–2.07), urinary tract infection (OR 1.83, 95% CI 1.55–2.16), and septicemia (OR 1.34, 95% CI 1.09–1.65). In conclusion, epilepsy was associated with higher risk of diabetes and adverse post-diabetes outcomes. Diabetes prevention and attention to post-diabetes adverse events are needed for this susceptible population.