Impact of COVID-19 infection on mortality, diabetic complications and haematological parameters in patients with diabetes mellitus: a systematic review and meta-analysis.

OBJECTIVES

SARS-CoV-2 poses significant challenges to people living with diabetes (PLWD). This systematic review aimed to explore the impact of COVID-19 on mortality, complications associated with diabetes and haematological parameters among PLWD.

DESIGN

Systematic review and meta-analysis using the Grading of Recommendations Assessment, Development and Evaluation (GRADE).

DATA SOURCES

EMBASE, MEDLINE, Cochrane Central Register of Controlled Trials and LILACS were searched between 1 December 2019 and 14 January 2025.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Eligible studies included case-control and cohort studies involving PLWD categorised into two groups: those with confirmed SARS-CoV-2 infection and those without.

DATA EXTRACTION AND SYNTHESIS

Meta-analyses estimated the odds ratios (ORs) and mean differences (MDs) of outcomes including mortality, intensive care unit (ICU) admission, diabetic ketoacidosis (DKA), acute kidney injury, hospitalisation length and haematological parameters. We pooled results using random-effects models and assessed study quality with the Newcastle-Ottawa Scale. A funnel plot was used to detect potential publication bias. The overall certainty of evidence was assessed using GRADE.

RESULTS

25 of 7266 unique studies were eligible, including 1 154674 PLWD (561 558 with COVID-19 and 593 116 without COVID-19). SARS-CoV-2 infection in PLWD was associated with significantly increased mortality (OR 2.52, 95% CI 1.45 to 4.36, I=99%), acute kidney injury (3.69, 95% CI 2.75 to 4.94, I=0%), random plasma glucose in subjects with type 1 diabetes (MD 20.38 mg/dL, 95% CI 7.39 to 33.36, I=0%), haemoglobin A1C in subjects with type 2 diabetes (0.21%, 95% CI 0.05 to 0.38, I=13%), creatinine (0.12 mg/dL, 95% CI 0.04 to 0.19, I=0%), C reactive protein (38.30 mg/L, 95% CI 4.79 to 71.82, I=82%) and D-dimer (1.52 µg/mL, 95% CI 0.73 to 2.31, I=0%). No significant differences were observed in the incidence of ICU admission and DKA, hospitalisation length, haemoglobin, leucocyte, lymphocyte, neutrophil to lymphocyte ratio, platelet, blood urea nitrogen, estimated glomerular filtration rate, procalcitonin, albumin, ferritin and bilirubin among PLWD with and without SARS-CoV-2 infection.

CONCLUSIONS

SARS-CoV-2 infection is associated with elevated risks of mortality and acute kidney injury and poor glycaemic control in PLWD, alongside increased levels of inflammatory and coagulation biomarkers. These findings underscore the urgent need for tailored clinical management strategies for PLWD with COVID-19.

PROSPERO REGISTRATION NUMBER

CRD42023418039.