Singh, Prachi

Although insufficient sleep is associated with increased cardiovascular risk, evidence of a causal relationship is lacking. We investigated the effects of prolonged sleep restriction on 24-hour ambulatory blood pressure (BP) and other cardiovascular measures in 20 healthy young participants (aged 23.4±4.8 years, 9 females), who underwent a randomized, controlled, crossover, 16-day inpatient study consisting of 4 days of acclimation, 9 days of sleep restriction (4 hours of sleep/night) or control sleep (9 hours), and 3 days of recovery. Subjects consumed a weight maintenance diet with controlled nutrient composition throughout. A 24-hour BP (primary outcome) and cardiovascular biomarkers were measured repeatedly. Polysomnographic monitoring was continuous. Comparing sleep restriction versus control sleep, 24-hour mean BP was higher (adjusted mean difference, day 12: 2.1 mm Hg [95% CI, 0.6–3.6], corrected P =0.016), endothelial function was attenuated ( P <0.001), and plasma norepinephrine increased ( P =0.011). Despite increased deep sleep, BP was elevated while asleep during sleep restriction and recovery. Post hoc analysis revealed that 24-hour BP, wakefulness, and sleep BP increased during experimental and recovery phases of sleep restriction only in women, in whom 24-hour and sleep systolic BP increased by 8.0 (5.1–10.8) and 11.3 (5.9–16.7) mm Hg, respectively (both P <0.001). Shortened sleep causes persistent elevation in 24-hour and sleep-time BP. Pressor effects are evident despite closely controlled food intake and weight, suggesting that they are primarily driven by the shortened sleep duration. BP increases are especially striking and sustained in women, possibly suggesting lack of adaptation to sleep loss and thus greater vulnerability to its adverse cardiovascular effects.

Introduction: Obesity is linked with heightened vulnerability to cardiovascular diseases including hypertension. Nonetheless, mechanistic studies addressing the effects of experimental weight gain on blood pressure are lacking. We sought to examine whether experimental weight gain raises ambulatory blood pressure in healthy individuals and identify any relationship between changes in blood pressure and changes in regional fat distribution. Methods: Twenty-six normal weight subjects were randomized to a 8-week period of weight gain through overfeeding (N=16; age 30.4±6.6 years, BMI 23.5±3.5 kg/m 2 ) or weight maintenance (N=10; age 27.1±7.7 years, BMI 23.6±2.7 kg/m 2 ). Measurements of body composition by dual-energy X-ray absorptiometry and abdominal computed tomographic scans and 24-h ambulatory blood pressure monitoring were obtained at baseline and at follow-up. Results: Overfeeding resulted in an increase in body weight of 3.7±1.5 kg ( p <0.001) in weight gainers, with increments seen in total (21994±8247.4 to 25180.7±8563.1 gr, p <0.001), visceral (61.6±32.7 to 75.5±30.9 cm 2 , p =0.002) and subcutaneous fat (135.5±77.4 to 167.9±82.9 cm 2 , p <0.001). No changes occurred in the maintenance group. Weight gainers exhibited an increase in 24-h systolic blood pressure at follow-up (113.7±8 to 117.7±7.9 mmHg, p =0.009) and mean blood pressure (MAP) (85.1±4.9 to 86.8±5.1 mmHg, p =0.02), while blood pressure was unchanged in controls. Changes in MAP were positively correlated only with changes in visceral fat (rho=0.452, p =0.02) but not with changes in weight or any other body composition measure. Conclusion: Modest weight gain leads to marked elevation in 24-h blood pressure in lean healthy subjects. The association between increased MAP and abdominal visceral fat accumulation suggests that visceral deposition of adipose tissue may contribute specifically and mechanistically to the enhanced risk of hypertension associated with weight gain.

Background Despite strenuous public health efforts, obesity rates continue to rise globally, and contribute importantly to increased cardiometabolic morbidity and mortality. Dietary habits play a key role in the development and progression of obesity, and are the target of choice in preventative and therapeutic programs. Although preclinical studies have shown that caffeine may exert anti‐adipogenic effects, in humans the implications of coffee consumption on risks of excess adiposity are unclear. Objective The objective of this study was to investigate the association between habitual coffee consumption and indices of total and regional body fat in healthy adults. Methods Seventy‐eight subjects (46 males, mean age 27.3±6.1 years) who took part in research studies conducted at the Mayo Clinic Cardiovascular/Sleep Laboratory and underwent body composition assessment were selected. Absence of cardiovascular or metabolic diseases was ascertained by physical exam and review of medical charts. Height, weight, waist and hip circumference measures were collected for computation of body mass index (BMI, kg/m 2 ) and waist‐to‐hip ratio (WHR). Measurements of total body fat percentage, upper body fat (kg), and lower body fat (kg) were obtained from dual‐energy X‐ray absorptiometry (DXA). Abdominal computed tomography (CT) was used to quantify subcutaneous adipose tissue (SAT, cm 2 ) and visceral adipose tissue (VAT, cm 2 ). Habitual coffee consumption (cups/day; range 0–3) was self‐reported and coded as a binary variable (yes/no). Results Sixty percent of the subjects (n=47) reported habitual coffee consumption. Age and gender distribution were comparable between groups (P=0.52 and P=0.73, respectively). There was no significant difference between those who reported consuming coffee and those who did not in terms of BMI (23.6±2.7 kg/m 2 vs 24±2.8 kg/m 2 , P=0.56) and WHR (0.85±0.08 vs 0.85±0.07, P=0.7). Likewise, body composition and fat distribution indices were similar between groups: total body fat percentage (coffee drinkers vs non‐coffee drinkers: 30.5±7.2% vs 28.6±7.8%, P=0.27), upper body fat mass (6.6±2.4 kg vs 6.6±3.1 kg, P=0.99), lower body fat mass (9.4±5.2 kg vs 8.4±4.1 kg, P=0.39), SAT (143.4±61.3 cm 2 vs 135.9±63.7 cm 2 , P=0.6), and VAT (57.7±35.5 cm 2 vs 70.3±44 cm 2 , P=0.22). Analysis stratified by gender did not reveal any differential effect of regular coffee consumption on body fat (all Ps>0.26). Conclusion In healthy, young individuals moderate habitual coffee consumption is not associated with measures of total or regional adiposity. Whether the anti‐obesity effects of caffeine emerge only when it is consumed in larger quantities remains to be determined. Support or Funding Information Research support: NC is supported by American Heart Association grant 16SDG27250156 and Mayo Clinic Center for Clinical and Translational Science grant Marie Ingalls Cardiovascular Research Career Development Fund. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .

Background Abdominal (ABD) and lower‐body (LB) fat depots exert opposing effects on cardiometabolic risk factors. However, molecular mechanisms underlying these differences are not completely understood. Studies suggest an inflammatory role of CD95 in obesity‐associated adipose tissue inflammation and dysfunction. Also, leptin deficiency is associated with increased CD95 expression. Objective To examine the expression of CD95 in the ABD and LB fat depots and to investigate leptin‐dependent CD95 regulation. Methods Transcription of CD95 and other adipokines was determined in paired subcutaneous abdominal (ABD) and lower‐body (femoral, LB) fat samples obtained from 29 healthy individuals (10 females, age: 29.4 ± 7.6 years, BMI: 24 ± 4.1 kg/m 2 ). The underlying mechanisms and down‐stream effects of altered CD95 expression were evaluated using differentiated human white preadipocytes (dHWP). Results Reduced mRNA expression of CD95 was apparent in adipose tissue obtained from LB fat depot [ABD: 4.30 (13.91 – 0.06), LB: 2.49 (10.88 – 0.04), p = 0.01]. mRNA expression of MCP1 [ABD: 0.51 (1.35 – 0.34), LB: 0.51 (1.21 – 0.28), p = 0.51], CCL5 [ABD: 6.60 (43.45 – 1.40), LB: 4.44 (11.28 – 1.27), p = 0.20], TNFα [ABD: 1.10 (6.14 – 0.03), LB: 0.07 (5.84 – 0.03), p = 0.30], and leptin [ABD: 21.86 (31.33 – 14.6), LB: 27.23 (41.69 – 20.35), p = 0.08] was not different between the two fat depots. A positive relationship between CD95 mRNA and other inflammatory cytokines was evident in both ABD (MCP1: ρ = 0.79, p < 0.001; CCL5: ρ = 0.83, p < 0.001; TNFα: ρ = 0.87, p < 0.001) and LB fat depot (MCP1: ρ = 0.87, p < 0.001; CCL5: ρ = 0.78, p < 0.001; TNFα: ρ = 0.83, p < 0.001). Furthermore, leptin‐dependent decreases in CD95 mRNA (p = 0.04) and protein expression (p = 0.03) was seen in dHWP. Also, 24 hour pre‐treatment of dHWP with leptin protected cells from FasL (p = 0.03) induced apoptosis. Conclusions Compared to ABD adipose tissue, LB fat has reduced transcription of CD95. Additionally, expression of CD95 mRNA was associated with increased expression of inflammatory cytokines in both ABD and LB subcutaneous fat. Moreover, we show that leptin may mediate decreases in CD95 expression thereby protecting adipose tissue from FasL mediated apoptosis. Our studies suggest that the decreased CD95 mRNA expression in LB fat depot may be related to higher localized leptin expression and possibly contribute to depot specific alterations in adipose tissue function and consequent cardiometabolic risk. Support or Funding Information Prachi Singh is supported by AHA grant‐in‐Aid 17GRNT33660138. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .

Background Osteoporosis, a condition associated with decreased bone density, contributes significantly to morbidity and mortality. Importantly, the incidence and economic burden of osteoporosis is rising partly due to increases in the aging population. Moreover, while the role of obesity on bone health is controversial, studies suggest that obesity alters bone density. Effects of obstructive sleep apnea (OSA), which is more prevalent in ageing and obesity, on any relationship between obesity and BMD are not well known. Objective To examine the effects of BMI and OSA on total and regional bone density. Methods A database of all research participants with nocturnal polysomnography and whole body dual energy X‐Ray absorptiometry scan (DEXA) was created. The study population included 72 subjects without OSA (AHI<5, Age: 29.1 ± 7.3 years, BMI: 24.3 ± 3.6 Kg/m 2 ) and 22 subjects with OSA (apnea hypopnea index, AHI>5; 4 females, Age: 43.3 ± 11.2 years, BMI: 30.8 ± 4.1 Kg/m 2 ). We examined the relationship between BMI and BMD in all our subjects. Linear regression models adjusted for age and BMI were used to assess changes in bone density in the presence of OSA. Additional analyses examining the effects of OSA in overweight and obese individuals (BMI>25 kg/m 2 ) and relationship between BMI and BMD in OSA subjects were also undertaken. Results Total body bone density in all our study subjects was positively correlated with BMI (Std Beta = 0.42, 95% CI 0.004 – 0.015, p < 0.001) but not age (Std Beta = 0.04, 95% CI −0.002 −0.003, p = 0.71) or presence of OSA (Std Beta = 0.042, −0.029 − 0.040, p = 0.75). Similarly, bone density in spine was increased with increases in BMI (Std Beta = 0.45, 95% CI 0.006 − 0.019, p = 0.0003) and not affected by age (Std Beta = 0.14, 95% CI −0.001 – 0.005, p = 0.23) or presence of OSA (Std Beta = 0.18, 95% CI −0.011 – 0.065, p = 0.16). Also, increases in BMD in pelvic region were only associated with BMI (Std Beta = 0.30, 0.001 – 0.019, p = 0.024). Age (Std Beta = −0.09, −0.005 – 0.002, p = 0.45) or presence of OSA (Std Beta = 0.19, −0.016 – 0.086, p = 0.17) did not alter BMD in pelvic area. Interestingly, overweight and obese subjects with OSA had a lower pelvic BMD compared to overweight and obese subjects without OSA (1.10 ± 0.12 g/cm 3 Vs. 1.19 ± 0.16 g/cm 3 , p = 0.043), even when OSA subjects had a higher BMI (31.4± 3.7 kg/m 2 Vs. 27.8± 3.2 Kg/m 2 , p = 0.001) and were older (43.4 ± 11.3 years Vs 30.6 ± 8.8 years, p<0.001). Also, the positive relationship between BMI and BMD was not present in OSA subjects in our study population (Total BMD: p = 0.73; Spine BMD: p = 0.94; Pelvic BMD: p=0.77). Conclusion A positive association between bone density and BMI was observed in our study population. However, this relationship was not evident in OSA subjects. Further, our study suggests that OSA may be accompanied by decreased bone density in the pelvic region. Cross‐sectional and longitudinal studies examining the effects of OSA on regional bone density, fractures, and frailty in BMI, age and gender matched populations are warranted. Support or Funding Information VKS and PS are supported by NIH grant HL65176 This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .

Background Increases in circulating free‐fatty acids (FFAs) contribute to obesity‐associated cardiometabolic pathology and may be considered a surrogate marker for adipose tissue dysfunction. However, alterations in FFA metabolism resulting from modest weight gain have not been previously evaluated. Objective Examine the changes in FFAs during modest weight gain in healthy individuals and to investigate the relationship between regional fat depots. Study Design We evaluated the effects of overfeeding in 8 healthy, non‐obese participants (4 men; age 29 ± 5.7 years; BMI: 25.1 ± 2.1 kg/m2). FFA concentrations were measured using liquid chromatography/mass spectrometry under fasting conditions and during oral‐glucose tolerance test (OGTT) at baseline and after 8 weeks of weight gain. Prior to the baseline and weight gain visits, subjects consumed isocaloric macro‐nutrient stable diet for three days (50% carbohydrate, 35% fat and 15% protein). Body composition and regional fat depots were assessed using dual‐energy X‐ray absorptiometry and abdominal computed tomography scans. Results Overfeeding was accompanied by 3.9 ± 1.6 kg weight gain (p=0.01) resulting from 2.9 ± 0.9 kg (p=0.01) increase in fat mass and 1.0 ± 0.9 kg (p=0.04) increase in fat‐free mass. Compared to baseline, fasting FFA (439 ± 162 μM vs. 368 ± 123 μM, p=0.55) and area under the curve (AUC) for FFA during OGTT (23319 ± 11686 μM. min−1 vs. 20495 ± 4847 μM.min−1, p=0.55) did not change with weight gain. However, at 120 min. of the OGTT FFA were significantly greater after weight gain (60 ± 18 μM vs. 77 ± 34 μM, p=0.04). We found a negative relationship between relative changes in visceral fat area and FFA at 120 min of glucose challenge (rho=−0.76, p=0.03). Furthermore, relative changes in fasting FFA and AUC for FFA during OGTT with weight gain were associated with baseline total fat mass (fasting FFA: rho=0.76, p=0.03; AUC FFA: rho=0.81; p=0.02) and baseline abdominal fat area (fasting FFA: rho=0.76, p=0.03; AUC FFA: rho=0.79; p=0.02). Conclusions Modest weight gain does not alter fasting FFA or overall FFA response to oral glucose challenge. However, our data suggest development of early stages of adipose tissue insulin resistance which is apparent via lesser suppression of FFA at 120 min. of OGTT. Furthermore, the relationships between fasting FFA, AUC‐FFA, and baseline fat mass suggest that individuals with high baseline adiposity may be more susceptible to develop adipose tissue insulin resistance with weight gain. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .

Background Increasing evidence suggests that insufficient sleep is associated with increased morbidity and mortality. Studies linking short sleep with metabolic derangements such as obesity, insulin resistance and dyslipidemia, are especially persuasive. Nevertheless, the vast majority of these data have been obtained from observational studies. We sought to evaluate the effects of 9 days of partial sleep deprivation compared to normal sleep on lipid profile in healthy subjects undergoing an in‐laboratory, experimental protocol. Methods Eight healthy, nonobese, normolipidemic subjects (4 males, age 25.4±6.8 years, body mass index 25.2±3.9 kg/m 2 ) completed a randomized, controlled, crossover, 16‐day in‐patient study. Each sequence consisted of a 4‐day acclimation period, followed by 9 days of experimental partial sleep deprivation (4 hours of sleep opportunity; 00:30 AM – 4:30 AM); or normal sleep (9 hours of sleep opportunity; 10:00 PM – 7:00 AM), and a subsequent 3‐day recovery segment. Subjects consumed a controlled, weight maintenance diet (15% protein, 55% carbohydrates, and 30% fat) during the study. Fasting blood samples for measures of total cholesterol, high‐density lipoprotein (HDL) cholesterol, low‐density lipoprotein (LDL) cholesterol, and triglycerides were obtained in both study sequences on Days 4, 7, 10, 13, and 16. Results Compared to normal sleep, experimental partial sleep deprivation did not cause significant changes in total cholesterol (partial sleep deprivation vs normal sleep: 160.1±21.8 mg/dL vs 164.9±23.7 mg/dL, P=0.724), HDL cholesterol (54.1±14.7 mg/dL vs 52±12.8 mg/dL, P=0.75), LDL cholesterol (86.5±18.9 mg/dL vs 89.5±19.7 mg/dL, P=0.329), or triglycerides (97.7±26.6 mg/dL vs 96.6±38.3 mg/dL, P=0.633). Analysis of time course of lipid values across study days did not reveal appreciable patterns (all P>0.295). Likewise, body weight was similar during both study sequences (partial sleep deprivation vs normal sleep: 69.6±14.2 kg vs 69.2±13.5 kg, P=0.459). Conclusions Experimental sleep restriction does not alter circulating lipids or weight in healthy subjects. Aberrant metabolic effects of insufficient sleep may be mediated by dietary intake and occur when access to food is unrestricted, or may emerge only after longer exposure to sleep curtailment. Support or Funding Information American Heart Association grant 16SDG27250156; National Institutes of Health R01 grants HL114676 and HL114024; European Union project FNUSA‐ICRC no. CZ.1.05/1.1.00/02.0123. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .

Background Numerous studies have identified an association between frequency of breakfast consumption and body weight in children and adolescents, indicating that those who skip this meal are more likely to gain weight and develop obesity in adulthood. However, few studies have examined the implications of infrequent breakfast consumption for obesity risk in the adult population, and available data are mixed. The purpose of this study was to investigate the role of breakfast consumption on obesity indices and weight gain in a sample of healthy adults. Methods The study sample was drawn from a cohort of consecutive subjects who were recruited for research studies at the Cardiovascular/Sleep Laboratory at Mayo Clinic from 2005 to 2017 and consisted of 347 healthy adults (215 males, mean age 35.5±15.4 years, ranging from 18 to 87 years old). Physical examination and review of medical records were conducted to ensure absence of overt disease. Measures of height, weight, waist and hip circumference were obtained. Body mass index (BMI, kg/m 2 ) and waist‐to‐hip ratio (WHR) were computed. Obesity was defined as BMI ≥30 kg/m 2 . Weight gain over the past year was quantified from self‐report. Frequency of breakfast consumption (times/week, range 0 to 7) was collected from questionnaire and coded as “never” (0 times/week), “infrequent” (1 to 4 times/week), and “frequent” (5 to 7 times/week). Only those who reported the same breakfast routine for ≥2 years were included in the analysis. Results Four percent of the sample (n=15) reported never consuming breakfast and 24% (n=85) reported eating it infrequently. Compared to the individuals who consumed it frequently, those who never or infrequently had breakfast were predominately men (P=0.049) and older (P=0.001). Waist circumference was larger in those who skipped breakfast in comparison to those who consumed it 1–4 times/week or 5–7 times/week (97.5±17.9 cm vs. 85.6±11 cm vs. 87.7±15 cm, respectively; P=0.017). There were no significant differences in hip circumference, WHR, or BMI across breakfast eating patterns. Prevalence of obesity tended to be higher among those who skipped breakfast than in those who ate it frequently (26.7% vs. 10.9%, P=0.074). Individuals who did not consume breakfast reported the greatest weight gain, followed by those who consumed it 1–4 times/week, while the lowest weight gain was reported by those who had breakfast 5–7 times/week (3.6±6.9 kg vs. 2±2.3 kg vs. 1.3±2.2 kg; P=0.002). In a multivariable model, skipping breakfast predicted weight gain independently of age, gender, and BMI (P=0.004). Conclusions Infrequent breakfast consumption is associated with indices of central obesity and weight gain, with these associations being more evident in individuals who never eat breakfast. Our findings on healthy adults are consistent with prior observations in the young, corroborating the concept that regular consumption of this meal is an important and independent contributor of healthy weight at all ages. Support or Funding Information American Heart Association grant 16SDG27250156; National Institutes of Health grants RO1 HL 114676 and HL 114024; CCaTS Early Stage Investigator Award. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .

Background Acute cardiac and vascular events, including myocardial infarction (MI) exhibit a peak onset between 6 AM and 11 AM. Plasminogen activator inhibitor‐1 (PAI‐1) is a main inhibitor of tissue‐plasminogen activator and a key indicator of prothrombotic state. Elevated levels of PAI‐1 have been linked to increased cardiac and vascular risk. Obstructive sleep apnea (OSA) has also been associated with increased risk of MI. Hypoxemia, as well as OSA, increase PAI‐1. We tested the hypothesis that the early morning after awakening is associated with higher PAI‐1 activity in subjects with acute MI who also have OSA. Methods We studied 56 subjects after acute myocardial infarction (mean age 60±2 years; BMI 28±1 kg/m 2 ). All subjects underwent complete overnight sleep polysomnography within 2 weeks after MI to assess for presence and severity of OSA. PAI‐1 activity was measured in all 56 subjects, first before sleep (at 9 PM), and then immediately after awakening in the morning (at 6 AM). A third measurement of PAI‐1 was obtained in all subjects at 11 AM. Results For the group, PAI‐1 activity almost doubled from 12.5±1.6 U/mL at 9 PM to 22.5±2.5 U/mL after waking at 6 AM and decreased to 14.2±2.4 U/mL by 11 AM (P<0.0001). Fifty seven percent of patients were observed to have OSA, with apnea hypopnea index of >10 events/hour. Sleep apnea did not contribute to further elevation of morning PAI‐1 activity level in acute MI patients (9 PM, 6 AM and 11 AM PAI‐1 activity respectively: no OSA 11.6±2.5 U/mL, 24.1±3.8 U/mL and 15.2±3.5 U/mL; OSA 13.3±2.1 U/mL, 21.1±3.3 U/mL and 13.3±3.3 U/mL; P=0.8 for between group comparison). Conclusions Increased PAI‐1 activity in acute MI patients may be an important mechanism underlying the early morning peak in cardiovascular events. The presence of OSA however does not appear to further accentuate the already elevated PAI‐1 activity in acute MI patients. In patients after acute MI, the diurnal variation in PAI‐1, rather than apnea, may drive the impaired fibrinolysis. Support or Funding Information ‐‐R01 grant HL65176‐‐This study was also supported in part by a gift to the Mayo Foundation by the Philips Respironics Foundation. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .