The aim of the present study was to synthesize the evidence available on the impact of subgingival periodontal treatment + antibiotic therapy on the reduction of systemic markers of inflammation [CRP (mg/L), and interleukins (pg/dl), TNF-α (pg/dl)] in patients with metabolic syndrome and periodontal disease, compared with supragingival periodontal treatment + placebo. The gene discussed is CRP; the disease is metabolic syndrome.