Sex Differences of Tooth Loss and Obesity on Systemic Markers of Inflammation

Sex as a Biological Variable in Oral Diseases: Evidence and Future Prospects

The interest of the scientific community on sex and gender differences in health and disease has increased substantially over the past 25 to 30 y as a result of a long process of events and policies in the biomedical field. This is crucial as compelling evidence from human and animal model studies has demonstrated that sex and gender influence health, molecular and cellular processes, and response and predisposition to disease. The present scoping review aims to provide a synthesis of sex differences in oral diseases, ranging from periodontal disease to orofacial pain conditions, from risk of caries development to apical periodontitis. Overall, findings from this review further support a role for sexual dimorphism influencing disease predisposition and/or progression in oral diseases. Of note, this review also highlights the lack of consideration of additional factors such as gender and other psychosocial and external factors potentially influencing oral health and disease. New conceptual frameworks capable of capturing multiple fundamental domains and measurements should be developed in clinical and preclinical studies to inform sex-based individualized preventive and treatment strategies.

Association between C-Reactive protein and periodontitis in an obese population from the NHANES 2009-2010

BACKGROUND

Various data have been obtained on the relationship between body mass index (BMI) and C-reactive protein (CRP) and periodontitis. The aim of this study was to determine whether CRP/BMI are associated with periodontitis using data from the National Health and Nutrition Examination Survey (NHANES) database.

METHODS

A cross-sectional analysis of data from 3602 participants in the 2009-2010 NHANES cycle was performed. The definition of periodontitis was used to divide participants into four groups according to the criteria of Eke. Correlations between CRP/BMI and periodontitis were tested for statistical significance by means of descriptive statistics, multivariate regression, and subgroup-stratified analyses, with and without adjustments for confounders (such as age and sex).

RESULTS

There were no statistically significant differences (p > 0.05) regarding BMI and the development of periodontitis. After adjustment for age, sex, race, marital status, annual family income, alcohol consumption, hypertension, smoking, chronic pulmonary disease, cardiovascular disease, diabetes, flossing, and arthritis, CRP correlated significantly with the development of periodontitis in the subgroups stratified by obesity, with an odds ratio (OR) of 1.2 (95% CI, 1.0 to 1.5).

CONCLUSION

Through data analysis, we found an association between CRP levels and periodontitis prevalence in the American population, although this association was only present in the obese population. While there are several hypotheses about the underlying mechanism, further studies are needed to validate these findings.

Systemic Inflammation, Endothelial Function, and Risk of Periodontitis in Overweight/Obese Adults

The network interaction between systemic inflammatory mediators, endothelial cell adhesion function, and adiponectin as mediators of the association between metabolic diseases and periodontitis has not been evaluated. The objective of this study is to assess whether the interaction of baseline serum levels of TNF-α, hs-CRP, ICAM-1, VCAM-1, and adiponectin leads to periodontitis. Five hundred and ninety-seven overweight/obese (overweight: BMI 25 to <30 kg/m2; obese: >30 kg/m2) adults, aged 40-65 years, with complete 3-year follow-up data were included. Generalized structural equation models with negative binomial regression were used to estimate the regression coefficient (β) for the outcome number of teeth with probing pocket depth (PPD) ≥ 4 mm and bleeding on probing (BOP) at 3-year follow-up for a 1 standard deviation unit increase (Δ = +1SD) in each biomarker. After adjusting for multiple covariates, baseline ICAM-1 and VCAM-1 had significant direct effects on increased log-transformed number of teeth with PPD ≥ 4 mm and BOP (β: 0.16; 95% CI: 0.02-0.30; β: 0.15; 95% CI: 0.02-0.30, respectively). Baseline hs-CRP showed a significant indirect effect via ICAM-1 on the log-transformed number of teeth with PPD ≥ 4 mm and BOP (β: 4.84; 95% CI: 0.27-9.42). Thus, elevated serum ICAM-1 and VCAM-1 have a significant direct effect and increased hs-CRP has a significant indirect effect on the predicted level of periodontitis at the 3-year follow-up among overweight/obese Hispanic adults.

Tooth loss, body mass index and cognitive function among middle-aged and older adults in China: Does gender matter?

BACKGROUND

Previous studies have shown a longitudinal association between tooth loss and cognitive function. Body mass index (BMI) is an essential applicable indicator of health status screening. However, the underlying mechanism among these factors remains unclear. This study aimed to determine the mediating role of BMI in the tooth loss-cognition relationship by gender among Chinese middle-aged and older adults.

METHODS

This is a prospective and cohort study. We used three waves of follow-up data (2011, 2013, and 2015) from the China Health and Retirement Longitudinal Survey, including 10,013 participants aged 45 years or above. Cognitive function was evaluated by Telephone Interview of Cognitive Status, words recall, and figure drawing. The cross-lagged panel model was applied to test the hypothesized model.

RESULTS

Tooth loss is associated with higher BMI and lower level of cognitive function. We found significant total effects (B = -0.017, P = 0.008), direct effect (B = -0.015, P = 0.022) and indirect effects (B = -0.002, P = 0.010) of tooth loss on cognition mediated through BMI only among middle-aged and older men. For middle-aged and older women, the total effect (B = -0.010, P = 0.125) and direct effect (B = -0.007, P = 0.249) were no more significant.

CONCLUSIONS

The longitudinal association between tooth loss and cognition was primarily indirect through BMI among middle-aged Chinese males but not women. Public health authorities should remind middle-aged and older males with tooth loss and high BMI to participate in timely medical checkups for improving cognition.

Factors Associated with Tooth Loss in General Population of Bialystok, Poland

Background: The aim of this study was to assess risk factors for tooth loss in the population of the city of Bialystok, in north-eastern Poland, taking into account the entire population and different age groups. The study included 1138 subjects divided into three subgroups: 20–44 years, 45–64 years, and 65–79 years. Participants were classified according to the number of teeth lost (0–8 vs. 9–28). Socio-economic variables, smoking history, and dental habits were collected through a questionnaire. Medical examinations provided data on the body mass index and the fasting blood glucose level. Data were statistically analysed using Mann-Whitney U, Student’s t, chi² tests, and binary logistic regression, p < 0.05. Results: For the general population, being female (OR 1.38, 1.07–1.79, p = 0.015), having secondary education (OR 4.18, Cl 2.97–5.87, p < 0.000), higher body mass index (OR 1.13, Cl 1.10–1.17, p < 0.000), higher fasting blood glucose level (OR 1.03 1.03–1.04, p < 0.000), being former smoker (OR 1.72, Cl 1.29–2.31, p < 0.000), ever smoker (OR 1.69, Cl 1.29–2.20, p < 0.000), current smoker (OR 1.62, Cl 1.15–2.29, p < 0.006), longer smoking period (OR 1.11, Cl 1.09–1.14, p < 0.000), last visit to the dentist over a year ago (OR 1.92, Cl 0.44–2.58, p < 0.000) and tooth brushing less than two times a day (OR 1.6, Cl 1.14–2.23, p < 0.006) were associated with losing more than 8 teeth. In the subgroup aged 20–44 years, only smoking duration was a risk factor for tooth loss (p = 0.02). For the middle-aged and oldest groups, education level (respectively p < 0.001, and p = 0.001), body mass index (respectively, p < 0.001, and p = 0.037), smoking status ever/former/current (respectively p < 0.001 and p = 0.002), smoking status never/ever (respectively p < 0.001 and p = 0.009), smoking duration (p < 0.001) were related to tooth loss. Additionally, in the elderly group, fasting blood glucose level (p = 0.044) and frequency of dental visits (p = 0.007) were related to tooth loss. We concluded that in the evaluated population, tooth loss was associated with socio-demographic, medical, and behavioural factors.

Importance of socioeconomic factors in predicting tooth loss among older adults in Japan: Evidence from a machine learning analysis

Prevalence of tooth loss has increased due to population aging. Tooth loss negatively affects the overall physical and social well-being of older adults. Understanding the role of socio-demographic and other predictors associated with tooth loss that are measured in non-clinical settings can be useful in community-level prevention. We used high-dimensional epidemiological data to investigate important factors in predicting tooth loss among older adults over a 6-year period of follow-up. Data was from participants of 2010 and 2016 waves of the Japan Gerontological Evaluation Study (JAGES). A total of 19,407 community-dwelling functionally independent older adults aged 65 and older were included in the analysis. Tooth loss was measured as moving from a higher number of teeth category at the baseline to a lower number of teeth category at the follow-up. Out of 119 potential predictors, age, sex, number of teeth, denture use, chewing difficulty, household income, employment, education, smoking, fruit and vegetable consumption, community participation, time since last health check-up, having a hobby, and feeling worthless were selected using Boruta algorithm. Within the 6-year follow-up, 3013 individuals (15.5%) reported incidence of tooth loss. People who experienced tooth loss were older (72.9 ± 5.2 vs 71.8 ± 4.7), and predominantly men (18.3% vs 13.1%). Extreme gradient boosting (XGBoost) machine learning prediction model had a mean accuracy of 90.5% (±0.9%). A visual analysis of machine learning predictions revealed that the prediction of tooth loss was mainly driven by demographic (older age), baseline oral health (having 10-19 teeth, wearing dentures), and socioeconomic (lower household income, manual occupations) variables. Predictors related to wide a range of determinants contribute towards tooth loss among older adults. In addition to oral health related and demographic factors, socioeconomic factors were important in predicting future tooth loss. Understanding the behaviour of these predictors can thus be useful in developing prevention strategies for tooth loss among older adults.

Obesity as a risk factor for tooth loss over 5 years: A population-based cohort study

AIM

To assess obesity as a risk factor for tooth loss over 5 years in an urban sample of Brazilian adults.

MATERIALS AND METHODS

A total of 1586 individuals were surveyed using a multistage probabilistic approach. Five years later, 635 individuals 14-64 years old were re-examined. An incident case of tooth loss was determined for a participant that had lost at least one tooth over time. Obesity was evaluated by calculating body mass index at baseline and by the change in obesity status over time.

RESULTS

Incident cases of tooth loss were significantly more frequent among obese (47.1%) than normal-weight individuals (32.4%) (p = .004). Obese individuals had 31% higher risk [relative risk (RR) =1.31; 95% confidence interval (95%CI) 1.04-1.65] for tooth loss than normal-weight individuals adjusting for age, socio-economic status, smoking, dental care and periodontitis. This association was significant for females (RR=1.47, 95%CI 1.08-2.01), but not for males. The risk for tooth loss was also modified by presence of periodontitis at baseline and lifetime smoking exposure. There was an increased risk for tooth loss for those that remained obese than those that remained normal weight.

CONCLUSION

Obesity is associated with higher risk for tooth loss. This association was modified by sex, periodontal status and smoking.

Tooth loss and adiposity: possible role of carnitine transporter (OCTN1/2) polymorphisms in women but not in men

OBJECTIVE

SLC22A4/5 single nucleotide polymorphisms (SNPs) have been reported to affect inflammatory diseases. We report the relationship of these polymorphisms with adiposity and tooth loss as elucidated in a 10-year follow-up study.

METHODS

Participants of the Study of Health in Pomerania (SHIP, N = 4105) were genotyped for the polymorphisms c.1507C > T in SLC22A4 (rs1050152) and -207C > G in SLC22A5 (rs2631367) using allele-specific real-time PCR assays. A total of 1817 subjects, 934 female and 883 male aged 30-80 years, underwent follow-up 10 years later (SHIP-2) and were assessed for adiposity and tooth loss.

RESULTS

The frequencies of the rarer SLC22A4 TT and SLC22A5 CC alleles were 16.7% and 20.3%, respectively. In women, tooth loss was associated with genotype TT vs. CC with incidence rate ratio IRR = 0.74 (95%C.I. 0.60-0.92) and CC vs. GG IRR = 0.79 (0.65-0.96) for SLC22A4 and SLC22A5 SNPs, respectively. In men, no such associations were observed. In the follow-up examination, the relationship between tooth loss and these SNPs was in parallel with measures of body shape such as BMI, body weight, waist circumference, or body fat accumulation. The association between muscle strength and body fat mass was modified by the genotypes studied.

CONCLUSIONS

SLC22A4 c.150C > T and SLC22A5 -207C > G polymorphisms are associated with tooth loss and markers of body shape in women but not in men.

CLINICAL RELEVANCE

Tooth loss may be related to obesity beyond inflammatory mechanisms, conceivably with a genetic background.

Association between tooth loss and handgrip strength in a general adult population

Tooth loss is a prevailing condition in China due to the high prevalence of oral diseases. Since previous studies explored the association between tooth loss and handgrip strength showed incongruous results, the aim of this study was to investigate the association between tooth loss and handgrip strength in Tianjin, China. Cross-sectional data in the present study used baseline data of Tianjin Chronic Low-grade Systemic Inflammation and Health (TCLSIH) Cohort Study during 2013–2016. Eligible adults (n = 26275) were classified into four groups depending on the number of missing teeth (excluding third molars): 0, 1–2, 3–5 and ≥6. Handgrip strength was measured using a handheld type dynamometer. Analysis of covariance was used to examine the relationships between tooth loss and handgrip strength and handgrip strength per body weight according to gender. After adjustment for potential confounders, the relationships existed between increasing categories of tooth loss and handgrip strength, as well as handgrip strength per weight. The data of stratified analysis showed that there was a trending association between decreased handgrip strength and fewer retained teeth both in males and females less than 60 years of age (P for trend <0.01); whereas no significant association 60 years of age or older. Moreover, loss of more than 3 teeth was significantly associated with reduced muscle strength (P <0.01). Tooth loss is independently associated with handgrip strength in Chinese adults less than 60 years of age.

Periodontitis, Low-Grade Inflammation and Systemic Health: A Scoping Review

Background and objectives: Periodontitis is a multifactorial chronic inflammatory infectious disease in which an infection is necessary, but not sufficient, for development of the condition. Individual susceptibility strictly linked to the immune and inflammatory response of the organism must also be present. Low-grade inflammation (LGI) is a systemic status of chronic sub-clinical production of inflammatory factors. This condition represents a risk factor for many chronic diseases including diabetes, cardiovascular disease, cerebrovascular disease, neurodegenerative disease and cancer. This scoping review aims to clarify, summarize and disseminate current knowledge on the possible link between periodontitis, LGI and systemic health. Materials and Methods: PRISMA Extension for Scoping Reviews guidelines were followed. An ad-hoc created keyword string was used to search the electronic databases of PubMed/Medline, Embase, The Cochrane Library and ClinicalTrials.gov. A hand search of specialized journals and their reference lists was also performed. Results: 14 studies that respected eligibility criteria were selected and analyzed. There is emerging evidence of strong links between periodontitis, LGI and systemic health. On the one hand, periodontitis influences the systemic status of LGI and on the other hand, the systemic production of inflammatory factors affects periodontitis with a bidirectional connection. Conclusions: LGI and the subsequent onset of a systemic inflammatory phenotype can be considered the common substrate of many chronic inflammatory diseases including periodontitis, with multiple mutual connections between them. Understanding of the biological principles and mechanisms underlying such a complex interrelationship could lead to significant improvements in the field of personalized diagnostics and therapeutic protocols.

Association between metabolic syndrome and tooth loss: A systematic review and meta-analysis

BACKGROUND

The authors conducted a systematic review and meta-analysis to verify the existence and level of scientific evidence concerning the association between metabolic syndrome (MetS), as the main exposure, and tooth loss (TL), as the outcome.

TYPES OF STUDIES REVIEWED

Through electronic databases and partially through gray literature, the authors identified observational studies in adults. The authors used no date or language restrictions. The authors evaluated the studies' methodological quality by using the Newcastle-Ottawa Scale. The authors conducted a random-effects model meta-analysis. The authors assessed the quality of evidence by using the Grading of Recommendations Assessment, Development and Evaluation criteria.

RESULTS

Twelve studies met the eligibility criteria, and 9 were retained for the meta-analysis. Most were cross-sectional studies with good methodological quality. Participants with MetS had fewer teeth (standardized mean difference, -2.77; 95% confidence interval, -4.56 to -0.98) and an increased likelihood of lacking functional dentition (odds ratio, 2.37; 95% confidence interval, 1.89 to 2.96) than did those without MetS. The overall quality of evidence was very low.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Better-conducted longitudinal studies are necessary to establish a causal relationship between MetS and TL to inform the best strategies to prevent TL in populations with MetS.

Association of mastication and factors affecting masticatory function with obesity in adults: a systematic review

Background

A substantial number of adults suffer from obesity, that is caused by the risk factor, masticatory dysfunction. The association between mastication and obesity, however, is inconclusive. This systematic review aims to provide literature regarding the association between mastication and factors affecting masticatory function, and obesity in adults.

Methods

Four electronic databases (PubMed, EMBASE, Cochrane Library, and Web of Science) were used to search for publications that met the following criteria: published between 2007 and 2016, written in English, and assessed the associations between mastication and obesity among the population aged ≥18 years. The included publications were analyzed based on the study design, main conclusions, and strength of evidence identified by the two authors who screened all the abstracts and full-text articles and, abstracted data, and performed quality assessments by using a critical appraisal tool, the Critical Appraisal Skills Programme Cohort Studies Checklists.

Results

A total of 18 articles (16 cross-sectional, 1 cohort studies, and 1 randomized controlled trial [RCT]) met our inclusion criteria and were evaluated. Poorer mastication was associated with obesity in 12 out of 16 cross-sectional studies. One cohort study showed that the obesity group displayed higher tooth loss than the normal weight group. One RCT demonstrated that gum-chewing intervention for 8 weeks significantly decreased waist circumference.

Conclusions

Most studies revealed a positive association between mastication and obesity among adults. Nonetheless, most of them are cross-sectional studies, which are insufficient to demonstrate a causal relation. Further advancement requires RCT, especially an intervention of improvement of mastication and obesity needed to confirm this association.

Electronic supplementary material

The online version of this article (10.1186/s12903-018-0525-3) contains supplementary material, which is available to authorized users.

Tooth loss and metabolic syndrome in middle-aged Japanese adults

AIM

Metabolic syndrome is associated with periodontal disease and dental caries; however, little attention has been given to the association between metabolic syndrome and tooth loss, which is the endpoint of these two diseases. This study examined this association in middle-aged adults over a 5-year period.

METHODS

A retrospective study was performed in 2107 participants (1718 males and 389 females) aged 35-60 years who underwent annual dental check-ups, to evaluate tooth loss and metabolic components, including obesity, elevated triglycerides, blood pressure, fasting glucose, and reduced high-density lipoprotein. Logistic regression analysis was performed to evaluate the association between metabolic syndrome (≥3 components) at the baseline examination and tooth loss.

RESULTS

Over a 5-year period, 10.8% of the participants lost at least one tooth. Compared to those with no metabolic components, participants with ≥3 components had an increased risk of tooth loss (odds ratio = 1.54; 95% confidence interval: 1.01-2.37), adjusting for age, gender, dental caries experience, attachment loss, oral hygiene status, number of teeth, tooth brushing frequency, smoking, and occupational status.

CONCLUSIONS

Metabolic syndrome was associated with the incidence of tooth loss among middle-aged adults.

Cross-sectional association between physical strength, obesity, periodontitis and number of teeth in a general population

AIM

Muscle strength declines and gums recede with increasing age across the life course. Possible associations exist between handgrip strength as an indicator of physical fitness and periodontitis and number of teeth.

MATERIAL AND METHODS

Handgrip strength (GS), anthropometric measures, clinical attachment loss, number of teeth, C-reactive protein and glycated haemoglobin were assessed in 2089 participants of the Study of Health in Pomerania (SHIP-2). Linear regression including interaction with age was used to estimate the association between clinical attachment level, number of teeth and GS.

RESULTS

In multiple regression adjusted for age, body mass index (BMI) and waist-to-hip ratio (WHR) each mm of diminished periodontal attachment was associated with reduction in GS by 1.47 kg (95% CI -2.29 to -0.65) and 0.38 kg (-0.89 to 0.14) in men and women respectively. Correspondingly, each additional remaining tooth was significantly associated with higher GS. Using handgrip strength relative to BMI as outcome, these relationships become even more apparent. Indicators of obesity such as BMI and WHR associated with both GS and periodontitis modulate the relationship between GS and periodontitis with a different impact between the sexes.

CONCLUSION

Periodontitis is associated with GS modified mainly by anthropometric measures related to adiposity and inflammation. Putative mechanisms encompass interactions of factors declining with increasing age.

Cross-Sectional Association Between Number of Teeth and High-Sensitivity C-Reactive Protein Among Middle-Aged Germans

BACKGROUND

The association between number of teeth and low-grade systemic inflammation deserves consideration within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam since the association between number of teeth and myocardial infarction has been established.

METHODS

Two subsamples (n = 2,439 and 728) were randomly selected from EPIC-Potsdam. Participants provided information on number of natural teeth, anthropometry, lifestyle factors, and illness-related factors. High-sensitivity C-reactive protein (hsCRP) was measured from serum. Adjusted means of hsCRP across five categories of numbers of teeth in each subsample and in the combined sample were determined, and linear trends were checked. Non-linear associations were investigated with restricted cubic spline (RCS) regression.

RESULTS

In the first subsample, the full multivariable-adjusted model showed that participants with 28 to 32, 24 to 27, 18 to 23, 1 to 17, and 0 teeth had mean hsCRP values of 1.32, 1.39, 1.54, 1.38, and 1.48 mg/L, respectively; in the second subsample, mean hsCRP values were 1.64, 1.67, 1.73, 1.47, and 1.87 mg/L; combined hsCRP values were 1.49, 1.53, 1.64, 1.44, and 1.65 mg/L. No linear trend was observed in these models, and RCS regression showed no non-linear association.

CONCLUSION

This study shows that number of teeth has a weak association with hsCRP, if any, thereby excluding this marker of low-grade systemic inflammation as a possible explanation for the association between number of teeth and myocardial infarction.

The association between subgingival periodontal pathogens and systemic inflammation

AIM

To investigate associations between periodontal disease pathogens and levels of systemic inflammation measured by C-reactive protein (CRP).

METHODS

A representative sample of dentate 60-70-year-old men in Northern Ireland had a comprehensive periodontal examination. Men taking statins were excluded. Subgingival plaque samples were analysed by quantitative real time PCR to identify the presence of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia. High-sensitivity CRP (mg/l) was measured from fasting blood samples. Multiple linear regression analysis was performed using log-transformed CRP concentration as the dependent variable, with the presence of each periodontal pathogen as predictor variables, with adjustment for various potential confounders.

RESULTS

A total of 518 men (mean age 63.6 SD 3.0 years) were included in the analysis. Multiple regression analysis showed that body mass index (p < 0.001), current smoking (p < 0.01), the detectable presence of P. gingivalis (p < 0.01) and hypertension (p = 0.01), were independently associated with an increased CRP. The detectable presence of P. gingivalis was associated with a 20% (95% confidence interval 4-35%) increase in CRP (mg/l) after adjustment for all other predictor variables.

CONCLUSION

In these 60-70-year-old dentate men, the presence of P. gingivalis in subgingival plaque was significantly associated with a raised level of C-reactive protein.

Association between periodontal disease and overweight and obesity: a systematic review

BACKGROUND

Periodontitis and obesity are among the most common chronic disorders affecting the world's populations, and recent reviews suggest a potential link between overweight/obesity and periodontitis. However, because of the scarcity of prospective evidence, previous reviews were primarily based on cross-sectional studies, with only a few longitudinal or intervention studies included. This study's objective is to examine the time-dependent association between obesity and periodontitis and how weight changes may affect the development of periodontitis in the general population. Therefore, longitudinal and experimental studies that assessed the association among overweight, obesity, weight gain, waist circumference, and periodontitis are reviewed.

METHODS

Intervention and longitudinal studies with overweight or obesity as exposure and periodontitis as outcome were searched through the platforms PubMed/Medline and Web of Knowledge.

RESULTS

Eight longitudinal and five intervention studies were included. Two of the longitudinal studies found a direct association between degree of overweight at baseline and subsequent risk of developing periodontitis, and a further three studies found a direct association between obesity and development of periodontitis among adults. Two intervention studies on the influence of obesity on periodontal treatment effects found that the response to non-surgical periodontal treatment was better among lean than obese patients; the remaining three studies did not report treatment differences between obese and lean participants. Among the eight longitudinal studies, one study adjusted for C-reactive protein (CRP) and biologic markers of inflammation such as CRP, interleukin-6, and tumor necrosis factor-α, and inflammation markers were analyzed separately in three of the five intervention studies.

CONCLUSION

This systematic review suggests that overweight, obesity, weight gain, and increased waist circumference may be risk factors for development of periodontitis or worsening of periodontal measures.