Circadian Rhythm Sleep Disorder, Shift Work Type

This prospective cross-sectional clinical study aims to investigate the relationship between circadian rhythm disruption and periodontal inflammation by evaluating circadian clock protein levels, inflammatory (IL-1beta) and anti-inflammatory (IL-10) cytokine levels in gingival crevicular fluid (GCF) of individuals with and without circadian rhythm disruption. Participants aged 20-50 years will be classified into four groups based on their circadian rhythm status (disrupted/normal) and gingival health status (gingivitis/healthy). Clinical periodontal parameters including plaque index, gingival index, bleeding on probing, and probing depth will be assessed. Circadian rhythm status will be determined using validated questionnaires (Morningness-Eveningness Questionnaire and Munich Chronotype Questionnaire). Night-shift workers will represent the circadian rhythm disruption group. GCF samples will be analyzed for circadian clock proteins (BMAL-1, CLOCK, PER-1, PER-2, PER-3, CRY-1, CRY-2, REV-ERB-beta, MTNR1B) and cytokines (IL-1beta, IL-10) using ELISA. Serum cortisol and melatonin levels will be measured for biochemical verification of circadian rhythm status. Gingivitis groups will receive standard periodontal treatment and be re-evaluated at 2 weeks post-treatment. A total of 116 participants (29 per group) are planned for enrollment.

The physiological processes of the body present daily oscillations called circadian rhythm. The circadian rhythm is essential for maintaining the vital functions of organisms, intervening directly and indirectly in a multitude of key processes, such as hormone secretion, cycles of activity and rest throughout the day, body temperature, the metabolism or absorption, processing and detoxification of nutrients. There are factors such as certain work schedules, prolonged exposure to screens, certain eating patterns or social jetlag, which have a negative impact on the circadian rhythm, causing its disruption and favoring the appearance of health alterations. Thus, there is evidence that associates night shift work with a higher incidence of risk factors for developing metabolic syndrome and cardiovascular diseases, including obesity, elevated blood levels of glucose, triglycerides, and low-density lipoprotein cholesterol (LDL-C), as well as lower levels of high-density lipoprotein cholesterol (HDL-C). In addition, disorders in the sleep cycle are associated with the development of hypertension and type 2 diabetes. Several previous studies show that a grape seed proanthocyanidin extract (GSPE) has beneficial effects on different parameters by restoring the circadian rhythm.