Corrigendum: Decreased step count prior to the first visit for MDD treatment: a retrospective, observational, longitudinal cohort study of continuously measured walking activity obtained from smartphones.

[This corrects the article DOI: 10.3389/fpubh.2023.1190464.].

Decreased step count prior to the first visit for MDD treatment: a retrospective, observational, longitudinal cohort study of continuously measured walking activity obtained from smartphones.

Introduction: Major depressive disorder (MDD) is a common debilitating psychiatric condition and a major cause of productivity loss in workers. Using intermittent, subjective indicators, previous studies have shown that physical activity can predict lower levels of depressive symptoms. However, there is an unmet need for continuous and objective measures to identify MDD development before it results in productivity loss. The aim of this study was to elucidate the association between continuously measured walking activity and the development of MDD. Methods: This retrospective, observational, longitudinal cohort study used health insurance claims data. Individuals aged 20-74 years were included if they had a record of MDD diagnosis and daily step count data for the 60 days before and after the first recorded MDD-related visit, which was defined as the index date. Multivariate analysis was conducted to compare 7-day moving averages of step counts on each day of the analysis period with the mean step count on the index date. Joinpoint regression analysis was used to determine when the trajectory of the moving step count average changed (inflection point). Results: In total, 2,143 patients with a mean age of 41.2 (standard deviation [SD]: 10.6) years were included. The majority of patients were men (69.5%) and employed full-time (94.1%). Antidepressants were prescribed for 59.2% of patients. The 7-day moving average step count decreased from 6,310 (SD: 3758) at day -60 to 5,879 (SD: 3183) at the index date (first recorded MDD-related visit), and then increased to 6,062 (SD: 4029) at day +60. Compared with the index date, the 7-day moving average of step counts was significantly higher at days -60 to -1, +23 to +33, and + 42 to +60, and significantly lower at days +2 and + 3. Joinpoint regression analysis of 7-day moving average step counts from day -60 to day 0 identified an inflection point at day -14. Conclusion: In working-age Japanese people, a formal diagnosis of MDD was preceded by a notable decline in daily step counts by approximately 2 weeks. MDD diagnosis and (presumed) treatment were followed by a gradual increase in daily step counts.

N epsilon-(hexanoyl) lysine, a new oxidative stress marker, is increased in metabolic syndrome, but not in obstructive sleep apnea.

BACKGROUND: It is well known that oxidative stress is induced by metabolic syndrome (MetS), leading to cardiovascular diseases. On the other hand, obstructive sleep apnea syndrome (OSAS) is frequently complicated with MetS, and OSAS is also considered to induce oxidative stress. Thus, we examined the plasma and urine markers of oxidative stress and antioxidant status in patients with OSAS with or without MetS. METHODS: Sixty-nine Japanese men suspected of having OSAS were recruited. We divided all patients into 3 groups: nonobese patients, obese patients without MetS, and patients with MetS. Oxidative stress markers, plasma and urine 8-hydroxydeoxyguanosine (8-OHdG) and plasma N epsilon-(hexanoyl) lysine (HEL), and an antioxidant status marker, plasma total antioxidant status, were measured by enzyme-linked immunosorbent assay. RESULTS: The plasma HEL level was significantly increased in patients with MetS, whereas neither plasma and urine 8-OHdG levels nor plasma total antioxidant status level was different in patients with MetS. Furthermore, the plasma HEL level was significantly and positively correlated with fasting plasma glucose, serum insulin, and homeostasis model assessment-insulin resistance index in all subjects. CONCLUSIONS: The oxidative stress is strongly associated with the presence of MetS but not related to the presence or severity of OSAS. Furthermore, we demonstrated that the plasma concentration of HEL is a more sensitive biomarker of oxidative stress in patients with MetS than the plasma and urine levels of 8-OHdG.

Serum levels of adipocytokines, adiponectin and leptin, in patients with obstructive sleep apnea syndrome.

OBJECTIVE: Obstructive sleep apnea syndrome (OSAS) is frequently complicated by metabolic syndrome, including diabetes and hypertension. Both OSAS and metabolic syndrome are strongly associated with obesity. Recently, adiponectin and leptin, which are secreted by adipose tissue, have been considered to play important roles in the progression of these diseases. Thus, to examine the association between leptin, adiponectin and OSAS, we measured the serum level of these adipocytokines in the same OSAS patients. METHODS AND PATIENTS: Sixty-eight consecutive Japanese men, who recorded all-night polysomnography, were enrolled in this study, and were divided into three groups, control (n=15), moderate OSAS (n=21) and severe OSAS (n=32). We measured serum levels of adiponectin and leptin by ELISA. RESULTS: Serum leptin levels were positively correlated with apnea hypopnea index (AHI) (r=0.552, p<0.001), the percentage of time with less than 90% hemoglobin saturation level in total sleep time (%T<90) (r=0.399, p<0.001) and body mass index (BMI) (r=0.807, p<0.0001). These parameters were suggested as the determinant factor for the serum leptin level by stepwise multiple regression analysis. On the other hand, serum adiponectin levels showed a positive correlation with age (r=0.361, p=0.005) and HDL-cholesterol level (r=0.274, p=0.039). Although there was no significant correlation between serum adiponectin levels and AHI or %T<90, serum adiponectin levels were chosen at a determinant factor of %T<90. CONCLUSION: These results suggested that the increasing severity of OSAS induces an increase in setum leptin concentration, but the serum adiponectin levels may be regulated independently of the degree of OSAS, obesity and serum leptin levels in patients with OSAS.