From the Guidelines
Hyperglycemia can lead to increased lactate levels in the body, particularly in diabetic patients, through enhanced glycolysis. When we consume excess sugar, particularly during high-intensity exercise or in certain medical conditions, our metabolism shifts toward anaerobic glycolysis, which produces lactate as a byproduct. This happens because the body cannot process all the glucose aerobically when oxygen supply is limited or when glucose levels are very high. Some key points to consider include:
- The relationship between sugar consumption and lactate levels is notable in diabetic patients, as hyperglycemia can lead to increased lactate production through enhanced glycolysis 1.
- In conditions like sepsis or liver dysfunction, the body's ability to clear lactate becomes impaired while sugar metabolism remains active, further elevating lactate levels.
- The connection between sugar and lactate is fundamental to understanding metabolic disorders and is relevant in clinical settings when interpreting laboratory values for patients with diabetes, critical illness, or during exercise assessment.
- A study published in the American Journal of Kidney Diseases in 2015 found that metformin use in patients with GFRs of 30 to 60 mL/min/1.73 m2 was associated with a reduction in 2-year mortality, and that there was no evidence of an increased risk of lactic acidosis or elevated lactate levels compared to other antihyperglycemic agents 1.
- Another study published in Clinical Nutrition in 2017 discussed the metabolism of fructose and its potential effects on lactate production, highlighting the complexity of carbohydrate metabolism and its impact on lactate levels 1.
From the Research
Hyperglycemia and Lactate Levels
- Hyperglycemia, or high blood sugar, is a common complication in patients with diabetes mellitus 2, 3, 4, 5, 6.
- The relationship between hyperglycemia and lactate levels is complex, and several studies have investigated this association 2, 4, 5, 6.
- Metformin, an oral anti-hyperglycemic agent, has been shown to reduce total mortality compared to other anti-hyperglycemic agents in the treatment of type 2 diabetes mellitus 2, 4.
- However, metformin is thought to increase the risk of lactic acidosis, a rare but serious condition characterized by elevated lactate levels 3, 5, 6.
Lactate Levels and Metformin Use
- Several studies have found no difference in lactate levels between metformin-treated patients and those receiving placebo or non-metformin therapies 2, 4.
- A study published in 2010 found that the upper limit for the true incidence of lactic acidosis per 100,000 patient-years was 4.3 cases in the metformin group and 5.4 cases in the non-metformin group 2.
- Another study published in 2006 found that the mean lactate levels were slightly lower for metformin treatment compared to phenformin, a biguanide that is no longer used due to its association with lactic acidosis 4.
- A review published in 2010 suggested that metformin may even be protective in cases of very severe lactic acidosis unrelated to the drug 5.
Prognostic Value of Lactate Levels
- A study published in 1999 found that neither arterial lactate levels nor plasma metformin concentrations were of prognostic significance in relation to mortality in metformin-treated patients with lactic acidosis 6.
- The study suggested that death in these patients appeared to be associated with other hypoxic disease or underlying ill health, rather than the accumulation of metformin or high arterial levels of lactate 6.
- The prognostic value of lactate levels in patients with hyperglycemia and metformin use is still unclear, and further research is needed to fully understand this relationship 2, 4, 5, 6.