Sociodemographic characteristics
Table 1 presents the sociodemographic characteristics of the participants, and the mean age of the participants was 31± 9 years. Most of them were aged 30-39 years (41.3%), followed by 18-29 years (38.2%). The majority of the respondents were male (82%) and belonged to the Brahmin/Chhetri ethnic group (47.2%), followed by Janajati (32.3%). Approximately 11% of the respondents had a family history of hypertension, 7.4% had a family history of diabetes, and 3.5% had a family history of both hypertension and diabetes. A total of 22.5% of respondents reported being current smokers. Similarly, nearly one-third (31.4%) of respondents currently drink alcohol. Most of the respondents (92%) used to engage in heavy exercise for at least 150 minutes per week. More than a quarter of the respondents (28.3%) were experiencing stress. According to the BMI classification, more than one-third of respondents (35.1%) were overweight, and 8.8% were obese.
Prevalence of NCDs
The prevalence of all three NCDs among respondents with various risk factors and covariates is shown in Table 1. Individuals aged 50 years and older had the highest prevalence of hypertension, prediabetes, and diabetes (42%, 25.8%, and 8.1%, respectively). In terms of sex, men had a greater prevalence of diabetes and hypertension (22% and 1.8%, respectively). However, the prevalence of prediabetes was greater in men (8.8%) and women (8%). The prevalence of the three NCDs among the various ethnic groups was not significantly different (p = 0.275).
A family history of hypertension alone, diabetes, or both was associated with the prevalence of these NCDs (prediabetes: 8.3%, 14.9%, and 25.7%; diabetes: 1.9%, 5.4%, and 2.9%; and hypertension: 28.7%, 20.3%, and 28.6%, respectively). Compared to those who were not currently smoking (17%), the prevalence of hypertension was greater among current smokers (28.1%). A greater prevalence of prediabetes (10.3%) and diabetes (4.5%) was found among current smokers than among those who were not currently smokers. The results showed that the prevalence of hypertension was greater among people currently consuming alcohol (29%). Similarly, the prevalence of prediabetes and diabetes was greater (12.1% and 2.6%, respectively) than that of individuals who were not currently drinking alcohol (7.1% and 1.2%, respectively). Additionally, the prevalence of prediabetes and diabetes was greater among those who did not exercise regularly (diabetes: 2.5% and prediabetes: 21.3%). All the above values were found to be statistically significant.
BMI was found to be significantly related to the incidence of NCDs. Among overweight people, 34.5% and 19.5% had hypertension and prediabetes, respectively; 30.8% and 10.7% had hypertension and prediabetes, respectively; and 10.8% and 5.8% had hypertension and prediabetes, respectively, among normal/underweight respondents. Diabetes was more prevalent (2.6%) in overweight people than in obese or normal/underweight people (1.1% in both).
Associations between NCDs and covariates
Table 2 illustrates the results of binary and multinomial logistic regression analyses carried out to determine the associations between NCDs and covariates. The prevalence of all 3 NCDs was significantly associated with age group. Respondents over 50 years of age had a greater risk of hypertension (OR: 6.22, CI 3.16-12.24), prediabetes (OR: 7.26, CI 3.1-17) and diabetes (OR: 19.62, CI: 2.9-130.8) than did those aged 18-29 years. Similarly, the probabilities of having hypertension (OR: 3.97, CI: 2.27-6.39), prediabetes (OR: 2.96, CI: 1.34-6.5), and diabetes (OR: 8.67, CI: 1.4-53.7) were greater among those aged 40-49 years. Compared to females, males were significantly more likely to have hypertension (OR: 1.28 CI: 1.27-4.37). However, the associations between diabetes and prediabetes with sex and between ethnicity and the probability of having all 3 NCDs were not found to be statistically significant. The study revealed a significant increase in the likelihood of having diabetes (OR: 9.05, CI: 1.99-41.0) among respondents with a family history of diabetes and a greater likelihood of having prediabetes (OR: 4.7, CI: 1.92-11.54) among respondents with a family history of both diabetes and hypertension in comparison with respondents who did not have a family history. Current smokers had a greater (OR: 5.59 CI: 1.75-17.90) chance of having diabetes than nonsmokers. Compared to respondents who were not currently drinking alcohol, those who currently drink alcohol had a greater chance of having hypertension (OR: 1.74 CI: 1.20-2.51) and prediabetes (OR: 1.73 CI: 1.04-2.86). Current smoking habits were not significantly associated with either hypertension or prediabetes, nor was current alcohol consumption habits associated with diabetes. Similarly, none of the three NCDs included in this study were associated with perceived stress. Those who engaged in intense physical activity were significantly less likely to have diabetes (OR: 0.26, CI: 0.04-1.57), prediabetes (OR: 0.2, CI: 0.10-0.40), or hypertension (OR: 0.48, CI: 0.26-0.87).
Respondents in the obese and overweight BMI groups were significantly more likely to have hypertension (OR: 4.05, CI: 2.40-6.84 and OR: 3.40, CI: 2.38-4.85). Similarly, obese and overweight individuals were more likely to have prediabetes (OR: 3.77 CI: 1.97-7.20 and OR: 1.87 CI: 1.13-3.09, respectively). BMI was not found to be associated with having diabetes.
Subgroup analysis of receiver operating characteristic (ROC) curves
Figures 1, 2 and 3 shows the ability of age and BMI AUC-ROC to predict hypertension, prediabetes, and diabetes risk. For hypertension, the age AUC was 0.71 (95% CI, 0.67–0.75), and the BMI AUC was 0.69 (95% CI, 0.65–0.72) (Figure 1); for prediabetes, the age AUC was 0.67 (95% CI 0.61–0.73), and the BMI AUC was 0.61 (95% CI, 0.54–0.68) (Figure 2); and for diabetes, the age AUC was 0.79 (95% CI, 0.693–0.91), and the BMI AUC was 0.61 (95% CI 0.47–0.74) (Figure 3). All these analyses showed a statistically significant ability to predict hypertension, prediabetes, and diabetes.