Originally discovered in the 1890s, the complement system has traditionally been viewed as a “compliment” to the body’s innate and adaptive immune response. However, emerging data have shown that the complement system is a much more complex mechanism within the body involved in regulating inflammation, gene transcription, attraction of macrophages, and many more processes. Sustained complement activation contributes to autoimmunity and chronic inflammation. Pulmonary hypertension is a disease with a poor prognosis and an average life expectancy of 2–3 years that leads to vascular remodeling of the pulmonary arteries; the pulmonary arteries are essential to host homeostasis, as they divert deoxygenated blood from the right ventricle of the heart to the lungs for gas exchange. This review focuses on direct links between the complement system’s involvement in pulmonary hypertension, along with autoimmune conditions, and the reliance on the complement system for vascular remodeling processes of the pulmonary artery. Furthermore, circadian rhythmicity is highlighted as the disrupted homeostatic mechanism in the inflammatory consequences in the vascular remodeling within the pulmonary arteries, which could potentially open new therapeutic cues. The current treatment options for pulmonary hypertension are discussed with clinical trials using complement inhibitors and potential therapeutic targets that impact immune cell functions and complement activation, which could alleviate symptoms and block the progression of the disease. Further research on complement’s involvement in interstitial lung diseases and pulmonary hypertension could prove beneficial for our understanding of these various diseases and potential treatment options to prevent vascular remodeling of the pulmonary arteries.

Research on the relationship between resistin levels, metabolic health, and obesity has produced inconsistent findings across different ethnic groups, making it unclear whether lower resistin levels are associated with these conditions in Mexican-Americans. This cross-sectional study investigated the relationship between resistin, metabolic health, and obesity in an adult Mexican-American cohort (n = 1511) using multivariable linear regression analysis. Related adipokines (leptin and adiponectin) were measured simultaneously. Participants were categorized into four groups by metabolic health (healthy/unhealthy) and obesity (obese/non-obese) status. “Metabolically unhealthy” was defined as ≥2 cardiometabolic abnormalities. Obesity was defined as a BMI ≥ 30 kg/m². We also investigated the associations of related proinflammatory cytokines, demographic/anthropometric variables, and medications with each outcome variable of interest. The results showed no statistically significant differences in resistin levels between the groups. Leptin was higher and adiponectin was lower in groups with obesity and/or metabolically unhealthy status. The resistin findings contrast studies in other populations, while other leptin and adiponectin findings confirm those seen in many ethnic groups. Thiazolidinedione use was associated with lower resistin, confirming earlier research. These findings suggest that resistin’s role in metabolic health may be different in Mexican-Americans compared to other populations.