Diabetes and periodontitis may increase risk of cardiovascular disease. Whether albuminuria, C-reactive protein (CRP), and socioeconomic factors, known as cardiovascular risks in subjects with poorly controlled diabetes, are independently associated with periodontal status in well-controlled diabetes remains to be elucidated. In 503 subjects with type 2 diabetes, the cross-sectional associations of clinical and socioeconomic factors with periodontal parameters were investigated. Periodontal parameters on all teeth included the probing pocket depth at 6 sites per tooth, bleeding on probing, the plaque score, tooth mobility, and the number of teeth. The subjects had a mean HbA1c value of 6.85% and a median CRP value of 0.06 mg/dL, and 27.9% of the subjects had albuminuria. Albuminuria and CRP values had significant associations with several periodontal parameters, whereas other variables including HbA1c did not. Subjects with albuminuria had significantly higher HbA1c, CRP, and % sites of pocket depth ≥ 4 mm than subjects with normoalbuminuria; additionally, those with high CRP (≥ median) had significantly higher body mass index, HbA1c, % sites of pocket depth ≥ 4 mm, and plaque score than those with low CRP. In multiple linear regression analysis, albuminuria, CRP, education, smoking, and dental attendance exhibited significant associations with periodontal parameters, independent of the effect of age, sex, body mass index, and diabetes therapy. Albuminuria, CRP, education, smoking, and dental attendance were independently associated with periodontal parameters even in subjects with a mean of HbA1c of 6.85%, implying the importance of these factors for the prevention of cardiovascular disease.

The decline in circulatory function with aging may be alleviated by a combination of gingival massage (physical stimulation) and mechanical cleaning. Several studies have reported the systemic effect of physical stimulation on various parts of the body, including its therapeutic effect on pain in the neck and shoulders that becomes evident with age, and improvement in blood circulation. In contrast, few studies have reported on the changes in gingival microcirculation induced by gingival massage, while no previous study has evaluated the effect of gingival microcirculation on age-related changes in the hemodynamics of the oral cavity. This study aimed to investigate how gingival massage affects age-related changes in gingival microcirculation. Male Wistar rats (7-week, 6-month and 1-year old) were prepared for a gingival massage group and a control group. Mechanical stimulation was applied on the maxillary molar gingiva for 5 seconds twice a week for 4 weeks. Subsequently, gingival reactive hyperemia was measured using a laser Doppler flowmeter. In addition, morphological analyses were also performed by hematoxylin and eosin and Indian ink staining and a vascular resin cast model. Base Flow, maximum response (Peak), and time required for the maximum response to halve (T 1/2) were reduced in 1-year-old rats compared with the other age groups. In the mechanical stimulated group, T 1/2 was increased in 7-week, 6-month, and 1-year-old rats, and total blood flow (Mass) was increased in 6-month and 1-year-old rats. In addition, clear blood vessel networks and loop-like revascularization were only observed in the mechanical stimulated group. Changes in age-related decline in gingival microcirculatory function and vascular construction were reported in this study, and the results suggested that gingival massage activates both the functional and morphological aspects of gingival microcirculation and may be effective for maintaining oral health.

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease that is prevalent worldwide. Non-alcoholic steatohepatitis (NASH) is an advanced form of NAFLD and carries the risk of progression from hepatic inflammation and fibrosis to cirrhosis and hepatocellular carcinoma. Pathological mechanisms of NAFLD have been proposed, such as the two-hit hypothesis and the multiple parallel hit hypothesis. Periodontal disease is a chronic infectious disease of the tissues surrounding the teeth that result in tooth loss. Several reports have indicated that periodontal infection is related to NAFLD. NAFLD and periodontal disease are chronic inflammatory conditions that are known as 'silent diseases'. Therefore, both conditions need to be detected early and treated under collaborative medical and dental care in order to prevent progression to NASH. For this purpose, further investigations in humans on the relationship between NAFLD and periodontal disease and on the effect of periodontal treatment on NAFLD are necessary. In this paper, studies on the relationship between NAFLD and periodontal disease are reviewed and a clinical study investigating the effect of periodontal treatment on NAFLD is introduced.Recent animal and human investigations have indicated that NAFLD/NASH is related to periodontal disease [13,14]. As patients with liver or periodontal disease have few subjective and early symptoms, the diseases are often severe when they are discovered at medical institutions. [15,16]. Therefore, early detection and treatment under collaborative medical and dental care is important to prevent progression to NASH, which may then develop into cirrhosis or liver cancer. Further investigations in humans on the relationship between NAFLD and periodontal disease and on the effect of periodontal treatment on NAFLD are desired. This paper reviews studies on NAFLD and periodontal