Cohort profile: Dehgolan prospective cohort study (DehPCS) on non-communicable diseases in a Kurdish community in the west of Iran

Prevalence of metabolic syndrome and its association with oral health: First results from the Kurdish cohort study

Aims

Investigate the association between oral and dental health (ODH) and metabolic syndrome (MetS) in adults aged 35-70 years.

Methods

The study utilized data from the enrollment phase of Dehgolan prospective cohort study in the west of Iran. A cross-sectional assessment was conducted on a total of 3996 participants, involving a comprehensive oral examination and the assessment of their oral hygiene behavior (ODH). MetS was defined according to the updated National Cholesterol Education Program Adult Treatment Panel III. Logistic regression used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for sociodemographic characteristics.

Results

MetS was more prevalent among those who not daily brushing and flossing. Participants with missing teeth (MT) show higher prevalent of MetS. Being female, lower age, illiteracy, family history of diabetes, low physical activity, and salt at table were independently associated with increase odds of MetS (p < 0.05). Odds of MetS were significantly decreased with use flossing (OR = 0.75; CI = 0.60-0.93), decayed (OR = 0.83; CI = 0.72-0.97), filled (OR = 0.84; CI = 0.71-0.99), and increased with MT (OR = 1.45; CI = 1.16-1.81) as long as adjusted for ODH factors. When other potential confounder such as sociodemographic, personal and nutritional habits were adjusted, daily flossing was the only factor that still statistically decreased (OR = 0.79; CI = 0.62-0.99) the odds of MetS.

Conclusion

Daily flossing was the only factor that independently associated with MetS. Relationship of other ODH factors with Mets were confounded by sociodemographic characteristics of the participants.

Socioeconomic inequalities in metabolic syndrome and its components in a sample of Iranian Kurdish adults

OBJECTIVES

The worldwide incidence of metabolic syndrome (MetS) has increased in recent decades. In this study, we investigated the socioeconomic inequalities associated with MetS and its components in a sample of the Iranian Kurdish population.

METHODS

We used data from 3,996 participants, aged 35 years to 70 years, from the baseline phase of the Dehgolan Prospective Cohort Study (February 2018 to March 2019). The concentration index and concentration curve were used to measure inequality and the Blinder-Oaxaca decomposition method was used to examine the contribution of various determinants to the observed socioeconomic inequality in MetS and its components.

RESULTS

The prevalence of MetS was 34.44% (95% confidence interval [CI], 32.97 to 35.93). The prevalence of MetS was 26.18% for those in the highest socioeconomic status (SES), compared with 40.51% for participants in the lowest SES. There was a significant negative concentration index for MetS (C=-0.13; 95% CI, -0.16 to -0.09), indicating a concentration of MetS among participants with a lower SES. The most prevalent component was abdominal obesity (59.14%) with a significant negative concentration index (C=-0.21; 95% CI, -0.25 to -0.18). According to decomposition analysis, age, gender, and education were the highest contributing factors to inequality in MetS and its components.

CONCLUSIONS

This study showed socioeconomic inequality in MetS. People with a low SES were more likely to have MetS. Therefore, policymakers and health managers need to develop appropriate strategies to reduce these inequalities in MetS across age groups, genders, and education levels, especially among women and the elderly.

Validity of self-reported hypertension and related factors in the adult population: Preliminary results from the cohort in the west of Iran

This study aimed to investigate the validity of self-reported hypertension and related factors in the Dehgolan Prospective Cohort Study (DehPCS). Data were obtained from 3996 participants aged 35-70 years in the enrolment phase of DehPCS. Self-reported hypertension and sociodemographic factors were collected by well-trained interviewers before hypertension diagnosis based on the reference criteria. The history of anti-hypertensive medication use and/or systolic blood pressure ≥140 (mmHg), or diastolic blood pressure ≥90 (mmHg) were considered as hypertension. Disagreement between self-reported and reference measures was assessed using sensitivity, specificity, positive, and negative predictive values (PPV and NPV), and kappa values. Binary and multinomial logistic regressions were used to investigate the correlates of validity of self-reported hypertension. The hypertension prevalence based on self-reports and the reference criteria was 19.49% and 21.60%, respectively. An acceptable percentage of kappa agreement value of 68.7% and relatively good overall agreement of 89.8% were found. Self-reported hypertension was guaranteed moderate sensitivity of 72.0% and high specificity of 94.5%, as well as the NPV and PPV of 92/7% and 77/9%, respectively. The chances of false-positive and false-negative reporting increased with older age, higher BMI, and a family history of hypertension. Being female, older age, higher BMI, concurrent diabetes, and stronger family ties to hypertension patients significantly increased the chance of reporting true positives relative to true negatives. Although, self-reported hypertension has an acceptable validity and can be used as a valid tool for screening epidemiological studies, it needs to be investigated because its validity is affected by age, gender, family history of hypertension, and other socio-demographic characteristics.

Prevalence of prediabetes, diabetes, diabetes awareness, treatment, and its socioeconomic inequality in west of Iran

We aim to estimate the prevalence of prediabetes, and diabetes mellitus (DM). We estimated awareness, treatment, plasma glucose control, and associated factors in diabetes, as well as, socioeconomic-related inequality in the prevalence of diabetes and prediabetes. Data for adults aged 35-70 years were obtained from the baseline phase of the Dehgolan prospective cohort study (DehPCS). Diabetes status was determined as fasting plasma glucose (FPG) of ≥ 126 mg/dl and/or taking glucose lowering medication confirmed by a medical practitioner. Prediabetes was considered as 100 ≤ FPG ≤ 125 mg/dl. The relative concentration index (RCI) was used to exhibit socioeconomic inequality in the prevalence of prediabetes and DM. Prevalence of prediabetes and DM, diabetes awareness and treatment, and glycemic control of DM 18.22%, 10.00%, 78.50%, 68.91% and, 28.50%, respectively. Increasing age (p < 0.001), Increasing body mass index (BMI) (p < 0.05), ex-smoker (p < 0.01), family history of diabetes (FHD) (p < 0.001), and comorbidity (p < 0.001) were independent risk factors for DM. Age group of 46-60 (p < 0.05), ex-smoker (p < 0.05), FHD (p < 0.05) were increased chance of awareness. Current smokers (p < 0.05), and higher education increase the chance of glycemic control in DM. Both DM (RCI =  - 0.234) and prediabetes (RCI =  - 0.122) were concentrated significantly among less-educated participants. DM was concentrated significantly among poor (RCI =  - 0.094) people. A significant proportion of DM awareness and treatment can be due to the integration of diabetes into the primary health care system. The high prevalence of prediabetes and diabetes, which is affected by socioeconomic inequality and combined with low levels of glycemic control may place a greater burden on the health system. Therefore, awareness, receiving treatment, and glycemic control in people with diabetes, and the socioeconomic status of people have become increasingly important in the near future.

Socio-demographic correlates of diabetes self-reporting validity: a study on the adult Kurdish population

BACKGROUND

In this research, data of the DehPCS study were used to assess the validity of self-reported diabetes based on the reference criteria, including the history of taking oral anti-diabetic drugs, insulin injection, or high fasting blood sugar.

METHODS

A cross-sectional analytical study was performed on 4400 participants of the DehPCS study, aged 35-70 years. The reference criteria were oral hypoglycemic drug consumption, insulin injection, and/ or fasting blood sugar ≥126 (mg/dl). The self-reporting diabetes was investigated by well-trained interviewers before the diabetes diagnosis based on the reference criteria. The validity of self-reporting diabetes was assessed using sensitivity, specificity, as well as positive and negative predictive values. Socio-demographic correlates of self-reported agreement were examined by multinomial logistic regression.

RESULTS

Three thousand nine hundred ninety-six people participated in this study, and the participation rate was equal to 90.8%. The diabetes prevalence among the study population was 13.1% based on self-reports and 9.7% based on the reference criteria. Five hundred twenty-three participants reported diabetes, 213 (41.28%) of whom did not have it. We found a good agreement of 92.3% with an acceptable kappa value of 65.1% between self-reporting diabetes and the reference criteria. Diabetes self-reporting also guaranteed sensitivity of 78.5%, specificity of 93.9%, as well as the positive and negative predictive values of 58.7% and of 98.0%, respectively. Being female, the higher economic class, the higher body mass index (BMI), and the positive family history of diabetes increased the chance of false positive. Being male, older ages and the moderate economic class increased the chance of false positive.

CONCLUSION

Self-reporting diabetes is identified as a relatively valid tool which could fairly determine the diabetes prevalence in epidemiological studies. It should be noted that its validity is influenced by some socio-demographic characteristics.