Sompalli, Sreeja

Abstract Background Obstructive sleep apnea (OSA) is a risk factor for hypertension and some evidence suggests this risk may not be mitigated with positive airway pressure. Low-intensity statin therapy can modestly reduce blood pressure (BP). In this exploratory analysis, we examined if six months of high-intensity statin therapy could lower resting or ambulatory BP in patients with OSA. Methods 39 patients with OSA (13F, age = 49 ± 9yrs, body mass index = 32.9 ± 4.2kg/m2, apnea-hypopnea index = 22.2 ± 12.4 events/hour) were randomized to high-intensity atorvastatin or placebo. BP was assessed using seated, “office” measurements and in 20-minute intervals over 24 consecutive hours at three timepoints (baseline, three- and six-months post-randomization). Participants maintained a diary denoting sleep and wake times for analysis. Changes (Δ) in BP from baseline were assessed and adjusted for adherence to participants’ intervention (atorvastatin or placebo) as well as to their treatment for OSA (yes or no). Results There were no between-group differences in baseline BP variables (P = .09-.96). At three months, the changes in resting (P = .74-.87), 24 hour mean (P = .54-.96), daytime (P = .70-.96), nor nighttime (P = .74-.96) BP did not differ between groups. Similarly, the changes in resting (P = .23-.92), 24 hour mean (P = .51-.82), daytime (P = .17-.78), and nighttime (P = .51-1.00) BP did not differ between groups following six months of their respective intervention. Conclusions Our data suggest that high-intensity atorvastatin does not lower resting or ambulatory BP in patients with OSA relative to a placebo. Thus, it does not appear that atorvastatin is a viable adjunct intervention for BP reduction in patients with OSA. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03308578.

Hypertension is commonly observed with obstructive sleep apnea (OSA), partly due to dysregulation of sympathetic activity. As OSA is considered male-dominant, potential sex differences in the sympathetic regulation of BP have yet to be explored. Hemodynamic responses to an orthostatic challenge have implications for cardiovascular risk and are sympathetically-modulated. Therefore, we tested the hypothesis that females with OSA have differential BP and HR responses to orthostasis relative to males with OSA. 160 individuals not taking antihypertensive medications completed an overnight polysomnography to identify OSA (apnea-hypopnea index ≥5 events/hr). Orthostatic responses were quantified as the changes (Δ) in BP and HR (assessed via brachial cuff) from rest (10min supine) to 60sec post-standing. Females with (n=17, 42±14yrs, 30.7±6.0kg/m2) and without (n=43, 39±12yrs, 27.6±5.7kg/m2) OSA were compared to males with (n=60, 45±11yrs, 31.4±3.8kg/m2) and without (n=40, 39±13yrs, 27.4±3.1kg/m2) OSA using a one-way ANOVA. There were no between-group differences in age (p>0.05 for post-hoc comparisons) and BMI was lower in both females, and males, without OSA relative to males with OSA (p<0.05 for both). ΔSBP did not differ between females with (1±8mmHg) and without (2±8mmHg) OSA nor between males with (4±8mmHg) and without OSA (5±12mmHg, ANOVA p=0.37). Females with OSA had a blunted ΔDBP relative to females without OSA (5±7 vs. 10±6mmHg, p<0.05), whereas males with and without OSA demonstrated similar responses (9±8 vs. 10±6mmHg, p=0.95). ΔHR did not differ between females with (8±8beats/min) and without OSA (9±11beats/min) nor between males with (13±10beats/min) and without OSA (12±10beats/min, ANOVA p=0.06). ΔDBP was not associated with the apnea-hypopnea index (Spearman's r=-0.19, p=0.47; Spearman’s r=0.23, p=0.08) nor nadir SpO2 (Spearman's r=0.27, p=0.29; Spearman’s r=0.06, p=0.64) in females or males with OSA. These data suggest that OSA influences the DBP response to orthostasis in females to a greater extent than males. As DBP is associated with sympathetic activation, this finding could indicate greater sympathetic dysregulation in females, relative to males, with OSA. This work was supported by the National Institutes of Health T32-HL007111 (JMB), HL134808 (NC), HL065176 (PS and VKS), and HL134885 (VKS). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Introduction: Growing evidence suggests that aberrant sleep architecture is linked to heightened risk of cardiovascular disease independently of sleep apnea. Rapid Eye Movement (REM) sleep is characterized by increased sympathetic activity and blood pressure (BP) compared to non-REM sleep stages. However, whether REM sleep is associated with BP across the 24 hours has not been investigated. Hypothesis: We hypothesized that increased REM sleep would be associated with higher ambulatory BP. Methods: We recruited 137 individuals (58% men, aged 39±14 years, office systolic/diastolic BP [SBP/DBP] 125±14/77±11 mmHg) who completed overnight polysomnography followed by 24-h ambulatory BP monitoring. Sleep was scored according to standard criteria. 24-h, daytime, and nighttime averages were calculated for SBP, DBP and heart rate. REM sleep duration was computed as percentage of total sleep time and used to group participants into tertiles as follows: T1 (REM% ≤18.8), T2 (REM% 18.9-24), and T3 (REM% ≥24.1). Results: Sex ratio, body mass index, and apnea-hypopnea index were similar across REM tertiles, but age increased with increasing tertiles (p=0.029). 24-h SBP (T1 vs T2 vs T3: 121±12 vs 117±7 vs 124±12 mmHg, p=0.015) and DBP (72±7 vs 70±6 vs 76±8 mmHg, p<0.001) differed across REM sleep tertiles, with significantly higher values in those in the highest tertile. Results were consistent when considering daytime SBP (T1 vs T2 vs T3: 126±12 vs 122±8 vs 132±14 mmHg, p<0.001) and DBP (77±7 vs 76±6 vs 83±9 mmHg, p<0.001), and nighttime DBP (65±9 vs 61±7 vs 65±8 mmHg, p=0.047). No differences were noted on nighttime SBP or any heart rate measures. A significant interaction was found between hypertension status and REM sleep in multiple regression analysis, with the observed associations being significant only among hypertensives (n=69). In those with hypertension, REM sleep duration was associated with 24-h mean BP independently of age, sex, body mass index, apnea-hypopnea index and antihypertensive medications (standardized beta 0.22, p=0.041). Conclusions: Longer REM sleep duration is independently associated with elevated ambulatory BP in individuals with hypertension. REM sleep may be a novel cardiovascular risk indicator in this population.

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 Dietary habits are critical determinants of health and especially of cardiometabolic risk status. Previous studies have examined the relationship between breakfast consumption and indices of obesity, with conflicting findings. Such discrepancy may be owed to the use of surrogate measures of adiposity such as body mass index. Furthermore, it is unknown whether frequency of breakfast consumption is associated with different patterns of regional body fat distribution. Objective In this study, we aimed at investigating the association between frequency of breakfast consumption and body fat distribution. Methods We compiled data from 184 individuals (64% males, mean age 35.8±12.6 years, ranging from 18 to 63 years old) who participated in research studies performed in the Mayo Clinic Cardiovascular/Sleep Laboratory from 2005 to 2019 and underwent whole body dual‐energy X‐ray absorptiometry (DXA) for body composition. Breakfast eating habits were assessed by questionnaire and frequency of consumption was determined as number of times per week (range 0 to 7). Responses were recoded as low frequency (0 to 2 times/week), middle frequency (3 to 4 times/week), and high frequency (5 to 7 times/week). Measures of height and weight were collected to compute body mass index (BMI, kg/m 2 ). Total body fat percentage, fat mass, and lean mass were obtained from DXA. Regions of interest were manually adjusted with the DXA software to quantify abdominal fat and lower body fat. Abdominal fat/total body fat and lower body fat/total body fat ratios were calculated. Results Low frequency of breakfast consumption was reported by 14% of the subjects (n=26), while 18% (n=34) reported middle‐frequency of consumption. The proportion of men/women (p=0.1) and BMI values (p=0.78) were similar across breakfast eating categories. Compared to those who had breakfast with high‐frequency, those who ate it less frequently were younger (p=0.038). In age, sex, and BMI‐adjusted analysis, low‐frequency of breakfast consumption was significantly associated with greater abdominal fat mass (standardized beta=0.11, 95% CI 0.09‐ 1.29, p=0.024) and higher abdominal fat/total body fat ratio (standardized beta=0.16, 95% CI 0.003–0.024, p=0.013). Total body fat percentage (p=0.26), fat mass (p=0.26), and lean mass (p=0.22) were not associated with frequency of breakfast consumption. Similarly, no relations were seen with lower body fat (p=0.85) or lower body fat/total body fat ratio (p=0.51). Conclusion Our study showed that infrequent breakfast consumption is selectively associated with greater abdominal fat mass. As accumulation of fat in the abdominal depot is a more robust predictor of adverse outcomes than total adiposity, these findings suggest that abdominal fat may mediate the increased cardiometabolic risk previously observed in conjunction with infrequent breakfast consumption.

Telomere length (TL) is associated with cardiovascular disease (CVD) and cancer. Obstructive sleep apnea (OSA) is also linked to higher risk of CVD and cancer, and to TL. We investigated the association between TL and risk of major adverse cardiac events (MACE) and cancer in OSA patients. We studied 210 individuals undergoing sleep-related studies between 2000 and 2007. Baseline characteristics and follow-up data (available in 164 subjects) were obtained from clinic records. Incidence rates were calculated for the entire group and by OSA status. Hazard ratios were calculated to estimate effects of OSA and TL on risk of MACE and cancer. In total, 32 individuals (20%) developed MACE and/or cancer during 12.7-year follow-up. The OSA group had a higher likelihood of cancer (16.0 vs. 4.9 events per 1000 person-years, P = 0.044) but no clear evidence of an elevated incidence of MACE (10.8 vs. 4.8 events per 1000 person-years, P = 0.293) compared to the non-OSA group. There was no association between TL and MACE- (HR = 1.01, 95% CI 0.78–1.28), or cancer-risk (HR = 1.18, 95% CI 0.96–1.43). Our study warrants further investigation of any modulating effect of OSA on TL and the risk of MACE and cancer.