Table 1. Sociodemographic characteristics of the included studies.

NOS: Newcastle-Ottawa Scale; CVD: cardiovascular disease; NM: not mentioned.

Study ID	Study design	Country	Sample size	Mean age	Gender (M)	Population type	NOS
Indriani et al. (2018) [23]	Case-control	Indonesia	20	65.13	7 (14.5%)	Anemia with inflammation	7
Šebeková et al. (2015) [24]	Cross-sectional	Germany	266	65	148 (55.6%)	Markers of inflammation in diabetic subjects	7
Lu et al. (2022) [25]	Cross-sectional	China	200	NM	NM	Idiopathic membranous nephropathy with high inflammatory markers	7
Perlstein et al. (2011) [26]	Cohort	USA	99	70.2	NM	Anemia with inflammation	6
Hao-Wei et al. (2021) [27]	Retrospective	China	138	63.42	55 (39.9%)	Chronic low back pain mediated by inflammatory markers	7
Ma et al. (2020) [28]	Case-control	China	10389	76.4 ± 13.3	NM	Diabetic patients with the pro-inflammatory effect of homocysteine	7
Jablonski et al. (2011) [29]	Cohort	USA	75	50-79 (range)	47 (62.7%)	Inflammation-linked vascular endothelial dysfunction	7
Laird et al. (2014) [30]	Observational study	Ireland	957	70.5	481 (50.3%)	Elderly with raised inflammatory markers	7
Cheng et al. (2022) [31]	Case-control	China	180	73.33 ± 5.55	90 (50.0%)	Elderly with mild cognitive impairment raised inflammatory markers	6
Verdoia et al. (2021) [32]	Cohort	Italy	1472	69.5	975 (66.2%)	Patients with CVD, metabolic syndrome, and elevation of cellular, and humoural inflammatory parameters	6
Dozio et al. (2015) [33]	Cohort	Italy	54	66	54 (100%)	Ulcerated melanoma and systemic inflammation	7
De Vita et al. (2014) [34]	Cross-sectional	Italy	867	75.1 ± 7.1	377 (43.5%)	Elderly with raised inflammatory markers (IL-6)	7