Table 1.
Peripheral insulin resistance and COVID-19.
| Relationship | Condition/Treatment | Patient Numbers * | Mean Age | Study Type | Date of Study | Inclusion Criteria | Population % | Main Findings | COVID-19 Mortality | Notes | Reference |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Diabetes worsenes COVID-19 outcome | Metabolic Syndrome | 46,441 | 61.2 ± 17.8 years old (SD) | Retrospective | 15 February 2020 to 18 February 2021 | Completed discharge status | 17.5% had metabolic syndrome | Increased risk of ICU admission, invasive mechanical ventilation, ARDS, and mortality; increased ICU and hospital LOS | Increased | MS defined as 3 or more conditions: obesity, prediabetes or diabetes, hypertension, and dyslipidemia) | [80] |
| Triglyceride and Glucose Index (TyG) | 151 | 59.5 ± 15.9 years old (SD) | Retrospective | 12 January 2020 to 13 Febreuary 2020 | Completed medical records and follow-up data | 25.8% had diabetes | TyG index levels were significantly higher in the severe cases and death group | Increased | TyG: marker of insulin resistance | [81] | |
| Diabetes | 1902 | 64 years old | Retrospective | 1 March 2020 to 27 September 2020 | COVID-19 | 31.2% had diabetes | 36% admitted to the ICU | 19% of those with diabetes died | [82] | ||
| COVID-19 increases risk for developing diabetes | Newly Diagnosed Diabetes Mellitus (NDDM) | 594 | 54.1 years old | Retrospective, with follow-up observations | 1 March 2020 to 27 September 2020 | COVID-19 and Diabetes | 13% had NDDM | Younger age in NDDM; NDDM had lower glucose levels but worsened COVID-19 (increased LOS, ICU admission); 56% still classified as DM at mean follow up of 323 days | No effect of NDDM | NDDM defined as fasting blood glucose >125–140 mg/dL or any glucose >140–180 mg/dL during admission | [82] |
| Development of diabetes | 551 | 61 ± 0.7 years old (SEM) | Retrospective | 1 February 2020 to 15 May 2020 | No pre-existing diabetes | 46% hyperglycemic; 27% normoglycemic | 12% had new classification of diabetes; and 18.5% had transient hyperglycemia; DM incread LOS; Glycemic abnormalities persisted for at least 2 months after resolved COVID-19 | DM increased | [83] | ||
| COVID-19 induction of diabetes | 124 | Non-severe COVID: 36.6 ± 15.8 years old; Severe COVID: 59.0 ± 13.9 years old (SEM) | Retrospective | 22 January 2020 to 7 April 2020 | No pre-existing diabetes | 25.8% had metabolic-related diseases | COVID-19 increased blood glucose and insulin levels compared to controls and persisted after virus elimination | Did not investigate | Compared to 30 non-COVID controls; looked into mechanism | [84] | |
| COVID-19 induction of diabetes | 64 | 44.3 ± 13.5 years old (SD) | Prospective | 17 January 2020 to 9 February 2020 (initial cohort) | No pre-existing diabetes | 84% had mild COVID; 15.6% had severe COVID | C-peptide and TyG indices increased with decreased fasting glucose levels up to 6 months post discharge | Followed patients at 3 and 6 months post hospital discharge | [85] | ||
| Treating COVID-19 with Diabetes Drugs | Metformin treatment | 6659 in the 3 observational studies | Systematic Review | Up to 30 July 2020 | English publications selected by 3 independent reviewers | 9 out of 14 articles | Positive benefit of metformin treatment in COVID-19 w/or w/o diabetes | 2/3 studies showed decreased mortality | Keywords used: COVID-19, SARS-CoV-2, 2019-nCoV, metformin, and antidiabetic drug | [88] |
* Patient numbers are numbers of admitted COVID-19 patients unless specified as specific population.