HDL-C and apolipoprotein A-I are independently associated with skeletal muscle mitochondrial function in healthy humans.

Prior animal and cell studies have demonstrated a direct role of high-density lipoprotein (HDL) and apolipoprotein A-I (ApoA-I) in enhancing skeletal muscle mitochondrial function and exercise capacity. However, the relevance of these animal and cell investigations in humans remains unknown. Therefore, a cross-sectional study was conducted in 48 adults (67% female, 8% Black participants, age 39 ± 15.4 yr old) to characterize the associations between HDL measures, ApoA-I, and muscle mitochondrial function. Forearm muscle oxygen recovery time (tau) from postexercise recovery kinetics was used to assess skeletal muscle mitochondrial function. Lipoprotein measures were assessed by nuclear magnetic resonance. HDL efflux capacity was assessed using J774 macrophages, radiolabeled cholesterol, and apolipoprotein B-depleted plasma both with and without added cyclic adenosine monophosphate. In univariate analyses, faster skeletal muscle oxygen recovery time (lower tau) was significantly associated with higher levels of HDL cholesterol (HDL-C), ApoA-I, and larger mean HDL size, but not HDL cholesterol efflux capacity. Slower recovery time (higher tau) was positively associated with body mass index (BMI) and fasting plasma glucose (FPG). In multivariable linear regression analyses, higher levels of HDL-C and ApoA-I, as well as larger HDL size, were independently associated with faster skeletal muscle oxygen recovery times that persisted after adjusting for BMI and FPG (all P < 0.05). In conclusion, higher levels of HDL-C, ApoA-I, and larger mean HDL size were independently associated with enhanced skeletal muscle mitochondrial function in healthy humans.NEW & NOTEWORTHY Our study provides the first direct evidence supporting the beneficial role of HDL-C and ApoA-I on enhanced skeletal muscle mitochondrial function in healthy young to middle-aged humans without cardiometabolic disease.

Potassium Magnesium Citrate Is Superior to Potassium Chloride in Reversing Metabolic Side Effects of Chlorthalidone.

BACKGROUND: Thiazide diuretics (TD) are the first-line treatment of hypertension because of its consistent benefit in lowering blood pressure and cardiovascular risk. TD is also known to cause an excess risk of diabetes, which may limit long-term use. Although potassium (K) depletion was thought to be the main mechanism of TD-induced hyperglycemia, TD also triggers magnesium (Mg) depletion. However, the role of Mg supplementation in modulating metabolic side effects of TD has not been investigated. Therefore, we aim to determine the effect of potassium magnesium citrate (KMgCit) on fasting plasma glucose and liver fat by magnetic resonance imaging during TD therapy. METHODS: Accordingly, we conducted a double-blinded RCT in 60 nondiabetic hypertension patients to compare the effects of KCl versus KMgCit during chlorthalidone treatment. Each patient received chlorthalidone alone for 3 weeks before randomization. Primary end point was the change in fasting plasma glucose after 16 weeks of KCl or KMgCit supplementation from chlorthalidone alone. RESULTS: The mean age of subjects was 59±11 years (30% Black participants). Chlorthalidone alone induced a significant rise in fasting plasma glucose, and a significant fall in serum K, serum Mg, and 24-hour urinary citrate excretion (all P<0.05). KMgCit attenuated the rise in fasting plasma glucose by 7.9 mg/dL versus KCl (P<0.05), which was not observed with KCl. There were no significant differences in liver fat between the 2 groups. CONCLUSIONS: KMgCit is superior to KCl, the common form of K supplement used in clinical practice, in preventing TD-induced hyperglycemia. This action may improve tolerability and cardiovascular safety in patients with hypertension treated with this drug class.

Utility of standing office blood pressure in detecting hypertension in healthy adults.

Current guidelines recommend office blood pressures (BP) be taken in a seated position when screening for hypertension (HTN). Seated BP is known to have limited accuracy in detecting high BP, while the utility of standing BP in diagnosing HTN is unknown. We conducted a cross-sectional study to determine the incremental value of standing BP in diagnosing HTN. Seated, standing, and 24-h ambulatory BPs (ABPM) were obtained in adults without known cardiovascular disease, HTN, or BP medication use. Presence of HTN was defined by the 2017 ACC/AHA and the 2023 ESH HTN guidelines based on ABPM. Area under the receiver-operating-characteristic curve (AUROC) was used to evaluate the diagnostic accuracy of seated and standing BP. Sensitivity and specificity of standing BP was determined using cut-offs derived from Youden's Index, while sensitivity and specificity of seated BP was determined using the cut-off of 130/80 mmHg and by 140/90 mmHg. Among 125 participants (mean age 49 ± 17 years; 62% female; 24% Black), 33.6% of them had HTN. Sensitivity and specificity of seated systolic BP (SBP) was 43% and 92%, respectively. Cut-offs selected by Youden's index for standing SBP/diastolic BP (DBP) were 124/81 mmHg according to the 2017 ACC/AHA HTN guidelines, and 123.5/83.5 mmHg according to the 2023 ESH HTN guidelines. Sensitivity and specificity of standing SBP was 71% and 67%, respectively. The AUROC of standing SBP (0.81 [0.71-0.92]) was significantly higher than seated SBP (0.70 [0.49-0.91]), when HTN was defined as average 24-h SBP ≥ 125 mmHg. Moreover, the addition of standing to seated SBP (0.80 [0.68-0.92]) improved HTN detection when compared to seated SBP. These patterns were consistent for both the 2017 ACC/AHA and the 2023 ESH definitions for HTN. In summary, standing BP, alone or in combination with seated BP, outperformed seated BP alone in diagnosing HTN in adults.

A generalized framework for the quantum Zeno and anti-Zeno effects in the strong coupling regime.

It is well known that repeated projective measurements can either slow down (the Zeno effect) or speed up (the anti-Zeno effect) quantum evolution. Until now, studies of these effects for a two-level system interacting with its environment have focused on repeatedly preparing the excited state via projective measurements. In this paper, we consider the repeated preparation of an arbitrary state of a two-level system that is interacting strongly with an environment of harmonic oscillators. To handle the strong interaction, we perform a polaron transformation and then use a perturbative approach to calculate the decay rates for the system. Upon calculating the decay rates, we discover that there is a transition in their qualitative behaviors as the state being repeatedly prepared continuously moves away from the excited state and toward a uniform superposition of the ground and excited states. Our results should be useful for the quantum control of a two-level system interacting with its environment.

MEN2B Masquerading as Postural Orthostatic Tachycardia Syndrome.

Multiple endocrine neoplasia type 2B is a genetic disorder characterized by pheochromocytoma, medullary thyroid carcinoma, and marfanoid features. Although hypertension and stress cardiomyopathy are known cardiovascular complications of pheochromocytoma, clinical presentation maybe subtle. Elevation in heart rate and lightheadedness induced by catecholamine excess may mimic clinical features of postural orthostatic tachycardia syndrome, as shown in our case report. (Level of Difficulty: Advanced.).

PRELIMINARY EXPERIMENTATIONS ON THE IN VITRO REARING OF HEMATOPHAGOUS PIGEON LOUSE HOHORSTIELLA LATA (AMBLYCERA: PHTHIRAPTERA: INSECTA).

Rearing hematophagous amblyceran lice in vitro is a challenging task. The hematophagous nature and active habits of amblycerans are distinct hurdles to in vitro rearing. The literature indicates only limited success in rearing the hematophagous amblyceran avian louse. Herein we report on the results of in vitro experimentation on an amblyceran pigeon louse, Hohorstiella lata. The incubation period of eggs was 5.47 ± 0.52 days. The durations of first, second, and third nymphal instars were 5.14 ± 0.55, 5.65 ± 0.83, and 6.35 ± 0.82 days, respectively. The average lifespan of adult females (7.45 ± 5.88 days) was higher than adult males (4.61 ± 3.57 days). Adult females laid a lifetime average of 3.73 eggs at a rate of 0.45 eggs/female/day under in vitro conditions (35 ± 1 C, 75-82% relative humidity, feather diet).