Background Depression is an important public health burden, vitamin D deficiency is associated with mood disorders. The risk of depression may increase with increasing age. Serum vitamin D levels and age are closely related. Objective This study is to investigate the association between vitamin D deficiency, age, and depression in a representative sample of US adults and the combined effect of vitamin D deficiency and aging on depression. Materials and Methods We extracted data from NHANES 2013–2018, including demographic characteristics, depression level, vitamin D level, physical activity, and body measures. Depression was screened by PHQ-9. Vitamin D was measured using the CDC method (test principle utilizing high performance liquid chromatography-tandem mass spectrometry to quantify 25OHD3, epi-25OHD3 and 25OHD2 in human serum). We performed binary logistic regression models to analyze the association between vitamin D, age and depression, respectively. Results A total of 15156 adults aged 20 years or older (mean age 49.81 ± 17.67 years, 7301 males and 7855 females) were included. Vitamin D levels were negatively associated with depression (P < 0.001). Vitamin D had a significant effect on depression (OR = 0.776, 95%Cl: 0.682–0.884, P < 0.001), the effect remained significant after adjusted for confounding variables (OR = 0.761, 95%Cl: 0.663–0.874, P < 0.001). Age was positively associated with depression (P < 0.001) and had a significant effect on depression (OR = 1.079, 95%Cl: 1.032–1.128, P = 0.001), the effect remained significant after adjusted for confounding variables (OR = 1.085, 95%Cl: 1.034–1.138, P = 0.001). Age and vitamin D levels were positively correlated (P < 0.001), and aging had a significant effect on vitamin D level (OR = 1.526, 95%Cl: 1.416–1.645, P < 0.001), the effect remained significant after adjusted for confounding variables (OR = 1.371, 95%Cl: 1.263–1.487, P < 0.001). In addition, the detection rate of depression was higher in females (2312/7855, 29.43%) than in males (1571/7301, 21.52%), and the difference was statistically significant (P < 0.001). Conclusions Vitamin D deficiency is a risk factor for depression; aging is a protective factor for vitamin D deficiency; Vitamin D and age synergetically affect the incident risk of depression: younger populations are more likely to present an increased risk of depression due to vitamin D deficiency; elderly females who are unmarried and living alone are the highest risk group for depression.

Background Depression is an important public health burden, its risk of occurrence is associated with vitamin D deficiency and may also increase with age, while serum vitamin D levels are closely related to age. Objective The purpose of this study was to evaluate whether vitamin D and age are associated with depression after adjustment for each other. Materials and methods We extracted data from NHANES 2013–2018, including demographic characteristics, depression level, vitamin D level, physical activity, and body measures. A total of 15,156 adults aged 20 years or older (mean age 49.81 ± 17.67 years, 7301 males and 7855 females) were included. Depression was screened by PHQ-9. Vitamin D deficiency was defined by a serum vitamin D level < 30nmol/L. We performed binary logistic regression models to analyze the association between vitamin D, age and depression, respectively. Results Vitamin D levels were negatively associated with depression (P < 0.001). Vitamin D had a significant effect on depression (OR = 0.776, 95%CI: 0.682–0.884, P < 0.001), the effect remained significant after adjusted for confounding variables (OR = 0.761, 95%CI: 0.663–0.874, P < 0.001). Age was positively associated with depression (P < 0.001) and had a significant effect on depression (OR = 1.079, 98%CI: 1.032–1.128, P = 0.001), the effect remained significant after adjusted for confounding variables (OR = 1.092, 95%CI: 1.040–1.146, P < 0.001). Age and vitamin D levels were positively correlated (P < 0.001), and older age had a significant effect on vitamin D level (OR = 1.526, 95%CI: 1.416–1.645, P < 0.001), the effect remained significant after adjusted for confounding variables (OR = 1.371, 95%CI: 1.263–1.487, P < 0.001). In addition, the prevalence of depression was higher in females (2312/7855, 29.43%) than in males (1571/7301, 21.52%), and the difference was statistically significant (P < 0.001). Conclusions Vitamin D deficiency and older age are both associated with higher risk of depression, while older age is a protective factor for vitamin D deficiency.

Background Young people who have just reached adulthood are prone to adverse reactions during various social adaptations, which can lead to depression. Depressive symptom among young adults is a severe public health burden currently deteriorating in progress. Smoking behavior, exposure to secondhand smoke in household and in various indoor settings may significantly affect depressive symptoms in young adults. Objective The purpose of this study was to evaluate whether recent tobacco smoking, household secondhand smoke exposure and confined space secondhand smoke exposure are associated with depressive symptom in young adults after adjustments for each other. Materials and Methods We extracted data from NHANES 2013–2018, including demographic characteristics, depression level, physical activity, current health status, body measures, recent tobacco smoking, household secondhand smoke exposure and confined space secondhand smoke exposure. A total of 4129 young adults age 18–35 years (mean age 26.11 ± 5.39 years, 2021 males and 2108 females) were included. Depressive symptom was screened by PHQ-9. Recent tobacco smoking and household secondhand smoke exposure were assessed by whether participants had smoked tobacco in the last five days and whether the living with a smoker who smoked inside the house. Confined space secondhand smoke exposure was assessed using the Secondhand Smoke Exposure Questionnaire in this study. We performed binary logistic regression models to analyze the association of recent tobacco smoking, household secondhand smoke exposure, confined space secondhand smoke exposure and depressive symptom, respectively. Results Recent tobacco smoking were positively associated with depressive symptom (OR = 2.201, 95% CI: 1.735–2.353, P < 0.001), this association remained significant after adjusted for confounding variables (OR = 1.593, 95% CI: 1.318–1.926, P < 0.001). Household secondhand smoke exposure was significantly associated with depressive symptom before adjustment for confounding variables (OR = 1.715, 95% CI: 1.479–1.989, P = 0.001), and this association was not statistically significant after adjustments (OR = 1.132, 95% CI: 0.942–1.360, P = 0.108). Confined space secondhand smoke exposure was positively associated with depressive symptom (OR = 1.812, 95% CI: 1.565–2.097, P < 0.001), this association remained significant after adjusted for confounding variables (OR = 1.399, 95% CI: 1.185–1.651, P < 0.001). Among the different settings of confined space secondhand smoke exposure, restaurant exposure (OR = 1.732, 95% CI: 1.120–2.678, P = 0.013) and in-car exposure (OR = 1.350, 95% CI: 1.102–1.652, P = 0.004) were significantly associated with depressive symptom after adjusted for confounding variables. Conclusions Recent tobacco smoking, restaurant and in-car secondhand smoke exposure are associated with greater risk of depressive symptom among U.S. young adults.

Background: Sleep disorder is an important psychological and public health burden, which seriously endangers physical and psychological health. Physical activities are closely related to sleep disorder, while different types of physical activities may have different effects on sleep disorder. Objective: The aim of this study was to evaluate the association of different types of physical activity on sleep disorder independent from each other. Materials and Methods: We extracted data from NHANES 2017-2018, including demographic characteristics, sleep disorder and physical activity. A total of 4157 adults aged 20 years or older (mean age 51.05 ± 17.52 years, 2029 males and 2128 females) was included. Types of physical activity (work, transportation, recreational physical activity and sedentary behavior) were defined and assessed by the Global Physical Activity Questionnaire (GPAQ); sleep disorder was assessed by patient self-report in the Munich Chronotype Questionnaire (MCTQ). Chi-square test and Kruskal-Wallis tests was used to compare differences between groups; the associations of each type of physical activity and sleep disorder were analyzed through binary Logistic regressions. Results: 1) 1211 participants were found to have sleep disorder, accounting for 29.1% of the total sample size; 2) There were significant differences in work physical activity (P=0.043), sedentary behavior (P<0.001) and recreational physical activity (P=0.001) among sleep disorder, the difference of transportation physical activity was close to significant (P=0.055). 3) Work physical activity (OR=1.249, 95% CI: 1.126-1.385, P<0.001) and sedentary behavior (OR=1.524, 95% CI: 1.330-1.745, P<0.001) were positively associated with sleep disorder, while recreational physical activity (OR=0.776, 95% Cl: 0.700-0.860, P<0.001) was negatively associated. Conclusions: 1) There are no significant associations between transportation physical activity and sleep disorder. 2) Both work physical activity and sedentary behavior are risk factors for sleep disorder. 3) Recreational physical activity is a protective factor for sleep disorder.

Background Lacking physical activity (PA) is an important risk factor for depression, the continuous decline of PA inevitably leads to the prolongation of sedentary behavior (SB) among adults, and limited evidence suggests that SB is also an independent risk factor associated with depression. Objective This study is to investigate the association between long-term sedentary behavior (LTSB) and depression in a representative sample of the American adult population using data from the National Health and Nutrition Examination Survey (NHANES). Materials and Methods Data from NHANES 2017–2018 were aggregated, including demographic information, degree of depression, PA, duration of sedentary behavior, body index, etc. PA was assessed by the Global Physical Activity Questionnaire (GPAQ). Depression was screened by a Patient Health Questionnaire (PHQ-9) in which includes several questions (Have little interest in doing things; Feeling down, depressed, or hopeless; Trouble sleeping or sleeping too much; etc.). Logistic regression was carried out to analyze associations between LTSB and depression. Results A total of 4728 adults (mean age 51.00 ± 17.49 years, 2310 males and 2418 females) were recruited in this study. The SB duration < 360 /d was negatively correlated with moderate to severe depression (r=-0.146, P = 0.029), while SB duration ≥ 720 min/d was a positive correlation with depression (r = 0.472, P = 0.001), significant correlations were not observed in other SB duration. LTSB had a significant effect on depression (OR = 1.484, 95% Cl: 1.176–1.817, P = 0.001), especially in moderate to severe depression (OR = 1.697, 95% Cl: 1.229–1.342, P = 0.001). The effects remained significant after adjusting for independent variables (OR = 1.429, 95% Cl: 1.122–1.820, P = 0.004), and this association was stronger in the occurrence of moderate to severe depression (OR = 1.586, 95% Cl: 1.139–2.210, P = 0.006). Furthermore, the detection rate of depression in females (710/2418, 29.36%) was higher than that in males (484/2310, 20.95%), and the difference was statistically significant (P < 0.001). Conclusions LTSB is a risk factor for depression, especially in moderate to severe depression. Middle-aged females who are not married tend to be the most likely to suffer from depression.