Do insulin resistance and chronic hyperglycemia drive chronic low-grade systemic inflammation?

Insulin resistance and chronic hyperglycemia are well-established drivers of a chronic, low-grade inflammatory state—often termed "metaflammation." This relationship is bidirectional: while inflammation can induce insulin resistance, metabolic dysfunction actively sustains and amplifies the inflammatory response through several distinct pathways.

Mechanistic pathways

The promotion of systemic inflammation by insulin resistance and hyperglycemia involves complex molecular signaling:

• Glucotoxicity and oxidative stress: Chronic hyperglycemia leads to the formation of advanced glycation end-products (AGEs) and excessive reactive oxygen species (ROS). These products activate the NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) signaling pathway, which is the primary transcription factor for pro-inflammatory cytokines.
• Innate immune activation: Elevated glucose and free fatty acids (FFAs) serve as metabolic triggers for the NLRP3 inflammasome and Toll-like receptor 4 (TLR4). Activation of these receptors in macrophages and other immune cells results in the secretion of potent inflammatory mediators, including interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α).
• Adipose tissue dysfunction: Insulin resistance in adipose tissue enhances lipolysis, releasing FFAs that further stimulate systemic inflammation, creating a self-perpetuating cycle of metabolic and immune stress.

Clinical indicators and biomarkers

High-sensitivity C-reactive protein (hs-CRP) is the standard clinical biomarker used to reflect this underlying inflammatory burden:

• hs-CRP as a proxy: Produced by the liver in response to IL-6, hs-CRP levels provide a stable measurement of the systemic inflammatory state. In chronic low-grade inflammation, hs-CRP typically remains persistently elevated in the range of 2.0 to 10.0 mg/L, whereas acute infections or trauma often drive levels above 100 mg/L.
• Dose-response relationship: Clinical data, such as those from the RISC study and various cardiovascular cohorts, demonstrate that hs-CRP levels rise in a dose-dependent manner alongside the severity of insulin resistance and the number of metabolic syndrome components. Levels ≥2.0 mg/L are formally recognized by the ACC/AHA and ESC as a "risk-enhancing factor" for cardiovascular disease.

Bottom line

Insulin resistance and chronic hyperglycemia are direct contributors to chronic low-grade systemic inflammation through oxidative stress and inflammasome activation. This state is reliably reflected in clinical practice by elevated hs-CRP (typically 2–10 mg/L), which serves as a validated marker for the inflammatory burden associated with metabolic dysfunction.