Association Between Sitting Time and Cardiometabolic Risk Factors After Adjustment for Cardiorespiratory Fitness, Cooper Center Longitudinal Study, 2010-2013

Iron Deficiency Related to Obesity

There is a direct correlation between being overweight and iron deficiency. Physiological changes occur in obese adipose cells that contribute to the development of iron deficiency (ID) and iron deficiency anemia (IDA). These changes disrupt the normal iron metabolic checks and balances. Furthermore, bariatric surgery can lead to long-term ID and IDA. Oral iron supplementation may not be effective for many of these patients. Intravenous iron infusions can significantly increase the quality of life for individuals experiencing this condition but are also associated with potentially serious complications. Adequate knowledge about intravenous (IV) iron administration can greatly increase the safety of this beneficial therapy. This review article explains the relationship between obesity, ID/IDA, bariatric surgery and the safe administration of IV iron.

Omega-3 index, cardiorespiratory fitness, and cognitive function in mid-age and older adults

Higher levels of omega-3 fatty acids in red blood cell membranes (omega-3 index or O3I) and cardiorespiratory fitness (CRF) are each associated with reduced cognitive impairment, but little research has examined the relationship between O3I and cognitive function while accounting for CRF. We analyzed cross-sectional data from 5,464 healthy men and women aged 55-85 years who had preventive medical examinations between 2009 and 2023. Primary exposures included O3I (<4.0%, 4.0-7.9%, or ≥ 8.0%) and age- and sex-based CRF quintile (1 = low, 2-3 = moderate, 4-5 = high). Cognitive impairment was defined as a Montreal Cognitive Assessment score of ≤ 25. We used Poisson regression to estimate relative risks (RR) of cognitive impairment, controlling for covariates. O3I < 4% was associated with increased cognitive impairment relative to ≥ 8.0% (RR, 1.21; 95% CI, 1.01-1.44) in a partially adjusted model. This association did not remain statistically significant in the fully adjusted model which included CRF. Low versus high CRF was associated with cognitive impairment (RR, 1.28; 95% CI, 1.07-1.53), independent of O3I and clinical biomarkers. The interaction between CRF and O3I was not significant (P = 0.8). In joint association analysis, risk of cognitive impairment was elevated with lower omega-3 index or CRF or both. Additional research is needed to fully understand the association between O3I and cognitive function at varying CRF levels.

Does breaking up sitting in office-based settings result in cognitive performance improvements which last throughout the day? A review of the evidence

Sedentary behavior at work contributes to detrimental cognitive outcomes (e.g., decreases in attention). The length of time that cognitive performance benefits are sustained following bouts of breaking up sitting (e.g., using sit-stand desks or walking) is not known. A narrative review of the literature was conducted using a systematic search strategy, with keywords related to breaking up sitting interventions in office-based environments and cognitive performance outcomes in the period immediately post the cessation of the breaking up sitting intervention. Three types of office-based breaking up sitting interventions were identified; 1) sit-stand desks, 2) walking desks and 3) cycling desks. From the eight studies which met the criteria, the impacts of these interventions on cognitive performance outcomes were mixed, with significant benefits in some studies and others reporting no benefit. Of the cognitive domains assessed, working memory, attention, and psychomotor function showed significant sustained improvement for up to 30 minutes post intervention. While there are benefits to a key set of cognitive performance domains following breaking up sitting interventions in office-based settings, no studies have evaluated whether benefits to cognitive performance persist for longer than 30 minutes after the breaking up sitting intervention. Furthermore, specific applications of these cognitive benefits to tasks outside of work (e.g., driving home from work) are unknown.

Sitting Time, Physical Activity, and Cognitive Impairment in Midlife and Older Adults

This study cross-sectionally examines the relations of sitting and physical activity (PA) with cognitive impairment in community-dwelling adults aged 55-87 years (n = 3,780). Multivariable logistic regression assessed independent and joint relations of sitting and PA with Montreal Cognitive Assessment scores adjusting for covariates. Sitting ≥75% of the time and not meeting PA guidelines were related to 60% (95% confidence interval [CI] [1.19, 2.17]) and 27% (95% CI [1.06, 1.53]) higher odds for cognitive impairment, respectively. Stratification by age showed that sitting ≥75% of the time was associated with higher cognitive impairment odds in midlife (odds ratio [OR] = 1.86; 95% CI [1.31, 2.65]), but not older adults (OR = 1.06; 95% CI [0.57, 1.95]). Joint association analysis revealed that, overall, the highest odds for cognitive impairment were in those sitting ≥75% of the time while meeting or not meeting PA guidelines (OR = 1.69, 95% CI [1.13, 2.53]; and OR = 1.66, 95% CI [1.19, 2.32], respectively). In conclusion, prolonged sitting and insufficient PA are independent risk markers for cognitive impairment.

Sedentary Behavior, Physical Inactivity, and Metabolic Syndrome: Pilot Findings From the Rapid Assessment Disuse Index Study

BACKGROUND

The Rapid Assessment Disuse Index (RADI) is a brief tool aimed to promptly assess primary care patients' overall physical inactivity and sedentary behavior. This study examines the relation between physical inactivity and sitting time (RADI) to cardiometabolic risk among primary care patients.

METHODS

Survey data and electronic medical record information were collated to explore the association between RADI scores (cumulative and sitting) to metabolic syndrome (and components) among women and men, using multivariable logistic regression.

RESULTS

Among women, the cumulative RADI score was not significantly associated with metabolic syndrome. However, the RADI sitting score was related to low high-density lipoprotein cholesterol and metabolic syndrome. That is, a transition to a higher RADI sitting score by 1 unit (vs remaining in the score) was related with a 1.4 and 1.3 times higher odds for having low high-density lipoprotein cholesterol (95% confidence interval, 1.05-1.87) and metabolic syndrome (95% confidence interval, 1.02-1.64), respectively. Among men, no significant relations were found.

CONCLUSIONS

The RADI sitting score is positively and significantly related to high-density lipoprotein and metabolic syndrome among women, yet not men. Due to the RADI's potential clinical utility, future research should attempt to examine these relations in larger, more robust samples and adjudicated outcomes using a prospective design.

Occupational sedentary behavior and prediction of proteinuria in young to middle-aged adults: a retrospective cohort study

BACKGROUND

Although sedentary behavior is a risk factor of cardiometabolic diseases and mortality, little information is available about a clinical impact of occupational sedentary behavior on chronic kidney disease (CKD).

METHODS

The present retrospective cohort study included 10,212 workers of a national university in Japan who underwent annual health checkups between April 2006 and March 2013. Main exposure of interest was self-reported occupational sedentary behavior at the baseline visit. The outcome was the incidence of proteinuria defined as dipstick urinary protein of 1 + or more. The association between sedentary workers and the incidence of proteinuria was assessed using Cox proportional hazards models adjusting for clinically relevant factors, including television viewing time, the major home sedentary behavior.

RESULTS

During median 4.8 years (interquartile range 2.1-7.9) of the observational period, the incidence of proteinuria was observed in 597 (12.0%) males and 697 (13.3%) females. In males, sedentary workers were identified as a significant predictor of proteinuria (multivariable-adjusted hazard ratio of non-sedentary and sedentary workers: 1.00 [reference] and 1.35 [1.11-1.63]), along with longer television viewing time (< 30 min, 30-60 min, 1-2 h, 2-3 h, and > 3 h/day: 1.15 [0.93-1.42], 1.00 [reference], 1.24 [1.00-1.53], 1.41 [1.03-1.93], and 1.77 [1.13-2.76]), whereas not daily exercise time. In females, neither sedentary workers nor television viewing time was associated with the incidence of proteinuria.

CONCLUSIONS

In conclusion, male sedentary workers were at high risk of proteinuria. Occupational sedentary behavior may be a potentially modifiable target for the prevention of CKD.

Relationship Between Sitting Time, Physical Activity, and Metabolic Syndrome Among Adults Depending on Body Mass Index (BMI)

Background

The aim of this study was to assess the possible relationship between sitting time and physical activity and the risk of occurrence of metabolic syndrome and its components. Analyses were conducted in the whole sample, and with stratification according to BMI. We have formulated a hypothesis that individuals with different BMIs have different responses to metabolic health modifiers such as physical activity and sitting time.

Material/Methods

Altogether, the data from 10 367 participants from urban and rural areas, aged 37–66 years were used in the study (7479 of whom were overweight or obese). The definition of metabolic syndrome devised by the IDF Joint Interim Statement criteria using an ethnic-specific cut-off point for waist circumference as the central obesity criterion was used.

Results

In all analyzed BMI groups, longer sitting time was only associated with abdominal obesity (all p for trend <0.05). In participants declaring low physical activity levels, the risk of metabolic syndrome and abnormal triglycerides concentration was higher compared to those declaring high physical activity, regardless of BMI (all p for trend <0.05). In the group with overweight or obesity, low physical activity was associated with a higher risk of abdominal obesity (p for trend <0.05), increased glucose concentration (p for trend <0.05), and elevated blood pressure (p for trend <0.05). In participants with a normal BMI, these associations did not occur.

Conclusions

Our data suggest that physical activity helps preventive metabolic syndrome and its abnormal components, especially in participants who are overweight or obese.

Visceral and Intrahepatic Fat Are Associated with Cardiometabolic Risk Factors Above Other Ectopic Fat Depots: The Framingham Heart Study

BACKGROUND

We examined the associations among 8 different fat depots accumulated in various anatomic regions and the relationship between these fat depots and multiple cardiometabolic risk factors.

METHODS

Participants were from the Framingham Heart Study Offspring and Third Generation who also participated in the multidetector computed tomography substudy in 2002-2005. Exposures were multidetector computed tomography-derived fat depots, including abdominal subcutaneous adipose tissue, abdominal visceral adipose tissue, intramuscular fat, intrathoracic fat, pericardial fat, thoracic periaortic fat, intrahepatic fat, and renal sinus fat. Multivariable-adjusted regression analyses with a forward selection procedure were performed to identify the most predictive fat depots.

RESULTS

Of 2529 participants, 51.9% were women (mean age, 51.1 years). Visceral adipose tissue had the strongest correlations with each of the other fat measures (range, 0.26-0.77) and with various cardiometabolic risk factors (range, -0.34 to 0.39). As determined by the selection models, visceral adipose tissue was the only fat depot that was associated with all cardiometabolic risk factors evaluated in this study (all P<.05). Selection models also showed that subcutaneous adipose tissue and intrahepatic fat were associated with cardiometabolic risk factors related to the traits of dysglycemia, dyslipidemia, and hypertension (all P<.05). However, only associations with visceral adipose tissue and intrahepatic fat persisted after further adjustment for body mass index and waist circumference.

CONCLUSIONS

Visceral adipose tissue and intrahepatic fat were consistent correlates of cardiometabolic risk factors, above and beyond standard anthropometric indices. Our data provide important insights for understanding the associations between variations in fat distribution and cardiometabolic abnormalities.