Peri-operative continuation of metformin does not improve glycaemic control in patients with type 2 diabetes: A randomized controlled trial

Current practice in the perioperative management of patients with diabetes mellitus: a narrative review

The prevalence of diabetes is increasing, and patients with diabetes mellitus have both an increased likelihood of requiring surgery and of developing postoperative complications when they do. We summarise available evidence underpinning current guidelines on preoperative assessment and optimisation, perioperative management of prescribed insulin and oral hypoglycaemic medication, intraoperative glycaemic control, and postoperative patient care.

[Position statement: surgery and diabetes mellitus (Update 2023)]

This position statement reflects the perspective of the Austrian Diabetes Association concerning the perioperative management of people with diabetes mellitus based on the available scientific evidence. The paper covers necessary preoperative examinations from an internal/diabetological point of view as well as the perioperative metabolic control by means of oral antihyperglycemic and/or insulin therapy.

Perioperative Management of Oral Glucose-lowering Drugs in the Patient with Type 2 Diabetes

The right management of oral glucose-lowering drugs aims to identify, assess, and follow patients with diabetes and avoid unnecessary interruptions of the chronic treatment.

Prognostic impact of elevated lactate levels on mortality in critically ill patients with and without preadmission metformin treatment: a Danish registry-based cohort study

BACKGROUND

Lactate is a robust prognostic marker for the outcome of critically ill patients. Several small studies reported that metformin users have higher lactate levels at ICU admission without a concomitant increase in mortality. However, this has not been investigated in a larger cohort. We aimed to determine whether the association between lactate levels around ICU admission and mortality is different in metformin users compared to metformin nonusers.

METHODS

This cohort study included patients admitted to ICUs in northern Denmark between January 2010 and August 2017 with any circulating lactate measured around ICU admission, which was defined as 12 h before until 6 h after admission. The association between the mean of the lactate levels measured during this period and 30-day mortality was determined for metformin users and nonusers by modelling restricted cubic splines obtained from a Cox regression model.

RESULTS

Of 37,293 included patients, 3183 (9%) used metformin. The median (interquartile range) lactate level was 1.8 (1.2-3.2) in metformin users and 1.6 (1.0-2.7) mmol/L in metformin nonusers. Lactate levels were strongly associated with mortality for both metformin users and nonusers. However, the association of lactate with mortality was different for metformin users, with a lower mortality rate in metformin users than in nonusers when admitted with similar lactate levels. This was observed over the whole range of lactate levels, and consequently, the relation of lactate with mortality was shifted rightwards for metformin users.

CONCLUSION

In this large observational cohort of critically ill patients, early lactate levels were strongly associated with mortality. Irrespective of the degree of hyperlactataemia, similar lactate levels were associated with a lower mortality rate in metformin users compared with metformin nonusers. Therefore, lactate levels around ICU admission should be interpreted according to metformin use.

Recent advances in diabetes treatments and their perioperative implications

PURPOSE OF REVIEW

The implications for perioperative management of new oral antihyperglycemic medications and new insulin treatment technologies are reviewed.

RECENT FINDINGS

The preoperative period represents an opportunity to optimize glycemic control and potentially to reduce adverse outcomes. There is now general consensus that the optimal blood glucose target for hospitalized patients is approximately 106-180 mg/dl (6-10 mmol/l). Recommendations for the management of antihyperglycemic medications vary among national guidelines. It may not be necessary to cease all antihyperglycemic agents prior to surgery. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are associated with higher rates of ketoacidosis especially in acutely unwell and postsurgical patients. The clinical practice implications of new insulin formulations, and new systems for insulin delivery, are not clear. The optimal perioperative management of these will vary depending on local institutional factors such as staff skills and existing clinical practices. Improved hospital care delivery standards, quality assurance, process improvements, consistency in clinical practice, and coordinated multidisciplinary teamwork should be a major focus for improving outcomes of perioperative patients with diabetes.

SUMMARY

Sulfonylureas and SGLT2i should be ceased before moderate or major surgery. Other oral antihyperglycemic therapies may be continued or ceased. Complex patients and/or new therapies require specialized multidisciplinary management.

Antihyperalgesia effect of AMP-activated protein kinase (AMPK) activators in a mouse model of postoperative pain

BACKGROUND AND OBJECTIVES

AMP-activated protein kinase (AMPK) activator drugs decrease hypersensitivity in mice with pain. This study examines if postsurgery treatment with the prototype AMPK activator metformin and a new mechanism-specific AMPK activator, O304, after plantar hindpaw incision in mice, would reduce mechanical hypersensitivity and produce changes in the AMPK pathway in the dorsal root ganglion (DRG).

METHODS

To create postoperative pain, an incision was made in the left plantar hindpaw. Animals were randomized into four oral gavage drug treatment groups (n=8/group): (1) vehicle, (2) metformin 200 mg/kg, (3) O304 200 mg/kg and (4) O304 200 mg/kg plus metformin 200 mg/kg. Drug gavages were performed 4 hours postsurgery and were repeated for 3 days. Mechanical hypersensitivity was measured with von Frey filaments. Changes in phosphorylated AMP-activated protein kinase alpha subunit, phosphorylated mechanistic target of rapamycin and phosphorylated eukaryotic initiation factor 2 alpha in DRG neurons were examined by immunohistochemistry.

RESULTS

O304 or metformin increased von Frey thresholds (reduced mechanical hypersensitivity) in plantar incision mice versus vehicle-treated incision mice between days 1 and 4 (difference of mean area under the curve, O304: 2.24 g*day; 95% CI of the difference 0.28 to 4.21, p=0.011; metformin: 2.56 g*day; 95% CI of the difference 1.71 to 3.41, p<0.001). The drug combination further elevated von Frey thresholds. In the vehicle-treated group, the AMP-activated protein kinase alpha subunit was downregulated and mechanistic target of rapamycin and eukaryotic initiation factor 2 alpha were upregulated in DRG neurons; these deficits were reversed by the AMPK activator treatments.

CONCLUSIONS

Early treatment with the mechanism-specific AMPK activator O304 or the prototype AMPK activator metformin reduces mechanical hypersensitivity in a postoperative pain model in mice. These drugs also normalize the AMPK pathway in the DRG.