Salivary free hemoglobin and lactate dehydrogenase as biomarkers for periodontal disease in smokers

Objective: The purpose of the present study was to compare levels of the biomarkers lactate dehydrogenase (LDH) and free hemoglobin in the saliva of different groups of smokers for early diagnosis of periodontitis and their clinical relevance for use as a screening tool. Method and materials: Eighty cigarette smokers were divided into light ( 10 cigarettes/day) moderate (10 to 19 cigarettes/day) and heavy (≥ 20 cigarettes/day) smokers. Stimulated saliva samples were obtained by the expectoration method and evaluated for LDH and free hemoglobin levels. Clinical parameters were recorded after saliva collection using the modified Community Periodontal Index (CPI). Results: Salivary free hemoglobin level was higher in light smokers compared to heavy smokers (mean 363.89 ± 295 µmol/L in light vs mean 79.55 ± 37.41 µmol/L in heavy, P = .001) and positively correlated with CPI score. There was no control group to prevent bias with free hemoglobin results in healthy individuals. Salivary LDH levels were higher in light smokers (411.24 ± 18.62 IU/L) compared to heavy smokers (313.26 ± 23.98 IU/L). However, a significant correlation between free hemoglobin, LDH, and CPI score (clinical parameters) was seen between the three groups of smokers (P .01). Conclusions: Within the limitations of this observational study, there was a progressive reduction in free hemoglobin and LDH levels from light smokers to heavy smokers. However, the severity of periodontal disease conditions increased as the severity of smoking habit increased. Keywords: lactate dehydrogenase, periodontitis, salivary hemoglobin, smoking