Voluntary Wheel Running Reduces Cardiometabolic Risks in Female Offspring Exposed to Lifelong High-Fat, High-Sucrose Diet

PURPOSE

Maternal and postnatal overnutrition has been linked to an increased risk of cardiometabolic diseases in offspring. This study investigated the impact of adult-onset voluntary wheel running to counteract cardiometabolic risks in female offspring exposed to a life-long high-fat, high-sucrose (HFHS) diet.

METHODS

Dams were fed either a HFHS or a low-fat, low-sucrose (LFLS) diet starting from 8 weeks prior to pregnancy and continuing throughout gestation and lactation. Offspring followed their mothers' diets. At 15 weeks of age, they were divided into sedentary (Sed) or voluntary wheel running (Ex) groups, resulting in four groups: LFLS/Sed (n = 10), LFLS/Ex (n = 5), HFHS/Sed (n = 6), HFHS/Ex (n = 5). Cardiac function was assessed at 25 weeks, with tissue collection at 26 weeks for mitochondrial respiratory function and protein analysis. Data were analyzed using two-way ANOVA.

RESULTS

While maternal HFHS diet did not affect the offspring's body weight at weaning, continuous HFHS feeding post-weaning resulted in increased body weight and adiposity, irrespective of the exercise regimen. HFHS/Sed offspring showed increased left ventricular wall thickness and elevated expression of enzymes involved in fatty acid transport (CD36, FABP3), lipogenesis (DGAT), glucose transport (GLUT4), oxidative stress (protein carbonyls, nitrotyrosine), and early senescence markers (p16, p21). Their cardiac mitochondria displayed lower oxidative phosphorylation (OXPHOS) efficiency and reduced expression of OXPHOS complexes and fatty acid metabolism enzymes (ACSL5, CPT1B). However, HFHS/Ex offspring mitigated these effects, aligning more with LFLS/Sed offspring.

CONCLUSIONS

Adult-onset voluntary wheel running effectively counteracts the detrimental cardiac effects of a lifelong HFHS diet, improving mitochondrial efficiency, reducing oxidative stress, and preventing early senescence. This underscores the significant role of physical activity in mitigating diet-induced cardiometabolic risks.

A Conserved Mechanism of Cardiac Hypertrophy Regression through FoxO1

The heart is a highly plastic organ that responds to diverse stimuli to modify form and function. The molecular mechanisms of adaptive physiological cardiac hypertrophy are well-established; however, the regulation of hypertrophy regression is poorly understood. To identify molecular features of regression, we studied Burmese pythons which experience reversible cardiac hypertrophy following large, infrequent meals. Using multi-omics screens followed by targeted analyses, we found forkhead box protein O1 (FoxO1) transcription factor signaling, and downstream autophagy activity, were downregulated during hypertrophy, but re-activated with regression. To determine whether these events were mechanistically related to regression, we established an in vitro platform of cardiomyocyte hypertrophy and regression from treatment with fed python plasma. FoxO1 inhibition prevented regression in this system, while FoxO1 activation reversed fed python plasma-induced hypertrophy in an autophagy-dependent manner. We next examined whether FoxO1 was implicated in mammalian models of reversible hypertrophy from exercise and pregnancy and found that in both cases FoxO1 was activated during regression. In these models, as in pythons, activation of FoxO1 was associated with increased expression FoxO1 target genes involved in autophagy. Taken together, our findings suggest FoxO1-dependent autophagy is a conserved mechanism for regression of physiological cardiac hypertrophy across species.

Attenuation of skeletal muscle atrophy via acupuncture, electro-acupuncture, and electrical stimulation

Background

Accelerated skeletal muscle wasting is a shared trait among many pathologies and aging. Acupuncture has been used as a therapeutic intervention to control pain; however, little is known about its effects on skeletal muscle atrophy and function. The study's purpose was to compare the effects of acupuncture, electro-acupuncture, and electrical stimulation on cast-induced skeletal muscle atrophy.

Methods

Forty female Sprague Dawley rats were randomly divided into groups: Control, casted (CAST), CAST+Acupuncture (CAST-A), 4) CAST+Electro-acupuncture (CAST-EA), and CAST+Electrical stimulation (CAST-ES) (n = 8). Plaster casting material was wrapped around the left hind limb. Acupuncture and electro-acupuncture (10 Hz, 6.4 mA) treatments were applied by needling acupoints (stomach-36 and gallbladder-34). Electrical stimulation (10 Hz, 6.4 mA) was conducted by needling the lateral and medial gastrocnemius muscles. Treatments were conducted for 15 min, three times/week for 14 days. Muscle atrophy F-box (MAFbx), muscle RING finger 1 (MuRF1), and contractile properties were assessed.

Results

Fourteen days of cast-immobilization decreased muscle fiber CSA by 56% in the CAST group (p = 0.00); whereas, all treatment groups demonstrated greater muscle fiber CSA than the CAST group (p = 0.00). Cast-immobilization increased MAFbx and MuRF1 protein expression in the CAST group (p<0.01) while the CAST-A, CAST-EA, and CAST-ES groups demonstrated lower levels of MAFbx and MuRF1 protein expression (p<0.02) compared to the CAST group. Following fourteen days of cast-immobilization, peak twitch tension did not differ between the CAST-A and CON groups (p = 0.12).

Conclusion

Skeletal muscle atrophy, induced by 14 days of cast-immobilization, was significantly attenuated by acupuncture, electro-acupuncture, or electrical stimulation.

Value of prolonged scrotal drainage after penile prosthesis implantation: a multicenter prospective nonrandomized pilot study

We aimed to understand the risks and benefits of post-inflatable penile prosthesis (IPP) implantation drainage and optimal duration. Our patients were divided into 3 groups: Group 1 (n = 114) had no drain placed, Group 2 had a drain placed for 24 h (n = 114) and Group 3 had a drain placed for 72 h (n = 117). Postoperative scrotal hematoma and prosthesis infection rates were compared between the groups. The patients from Group 3 demonstrated a statistically significant lower incidence of hematoma on the 10th postoperative day: (n = 1, 0.9%) compared to Group 2: (n = 11, 9.6%) and Group 1: (n = 8, 7%), (p = 0.013). However, on the 3rd postoperative day, there was a statistically significant lower incidence of hematoma in both Groups 3 and 2: (0.9% and 6.1%, respectively) vs. Group 1: (11.4%), (p = 0.004). Hematoma rates followed the same group order after the first day of surgery: 1.7% (n = 2), 5.3% (n = 6), and 8.8% (n = 10), respectively, (p = 0.05). Five patients (4.4%) in Group 1 and four patients (3.5%) in Group 2 developed an IPP associated infection, opposed to only a single patient (0.85%) in Group 3, (p = 0.210). We concluded that prolonged scrotal drainage for 72 h after virgin IPP implantation significantly reduces hematoma and infection rates.

Food insecurity and academic function among college students during the COVID-19 pandemic: A moderating role of the first-generation college student status

OBJECTIVE

To examine food insecurity (FI) prevalence among college students during the COVID-19 pandemic (April 2021) using cross-sectional design, and the moderating role of the first-generation student status in the relationship between FI and grade point average (GPA).

PARTICIPANTS

Three-hundred sixty students recruited mostly from upper-level kinesiology courses.

METHODS

General linear model was used to predict GPA based on food security status, psychological health, and bodily pain, with subgroup analysis performed by first-generation student status.

RESULTS

Approximately 19% were classified as having FI. Those with FI showed lower GPA and poor health compared to those without FI. The link between FI and GPA was moderated by first-generation student status, with the negative impact of FI on GPA more clearly observed among non-first-generation students.

CONCLUSION

First-generation student status could play a role in determining the impact of FI on academic performance.

A synthesis of a rationally designed inhibitor of cytochrome P450 8B1, a therapeutic target to treat obesity

Mice that lack the gene for expression of cytochrome P450 8B1 (P450 8B1) resist weight gain and improve glucose tolerance when fed a high-fat diet. Thus, the inhibition of P450 8B1 is a target to treat obesity-associated metabolic disorders. P450 8B1 is the enzyme that hydroxylates its substrate, 7α-hydroxy-cholest-4-en-3-one to 7α-,12α-dihydroxycholest-4-en-3-one, which ultimately results in the formation of cholic acid. Cholic acid is the 12α-hydroxylated bile acid implicated in enhanced absorption of cholesterol. The synthesis of a rationally designed inhibitor for P450 8B1 was achieved through the incorporation of a C12-pyridine in the C-ring of a steroid molecule. Seven days of new inhibitor treatment showed attenuation of glucose intolerance in mice that were fed a high fat and a high sucrose diet (HFHS) without affecting body weight. Taken together, these promising results will lead to a P450 8B1 inhibitor as a potential therapeutic strategy to treat obesity-associated insulin resistance.

Normal ranges of global left ventricular myocardial work indices in adults: a meta-analysis

Background

Non-invasive global myocardial work recently emerged as new parameter to characterize left ventricle function with potential advantages over both ejection fraction and global longitudinal strain.

Purpose

We aimed to perform a meta-analysis of normal ranges of non-invasive left ventricular myocardial work (MW) indices including global constructive work (GCW), global work index (GWI), global wasted work (GWW), and global work efficiency (GWE) and to identify confounding factors that may contribute to variance in reported measures.

Methods

The authors searched four databases, Pubmed, Scopus, Embase, and Cochrane Library through January 2021 using the key terms “myocardial work”,“global constructive work”, “global wasted work”, “global work index”, “global work efficiency”. Studies were included if the articles reported LV myocardial work using 2D transthoracic echocardiography in healthy normal subjects, either in the control group or comprising the entire study cohort. The weighted mean was estimated by using the random effect model with a 95% confidence interval. Heterogeneity across studies was assessed using the I2 test. Publication bias was examined by funnel plot and Egger's regression test.

Results

The search yielded 476 articles. After abstract and full text screening we included 13 datasets with 1665 patients for meta-analysis. The reported normal mean values of GCW and GWI among the studies were 2278 (95% CI, 2167 to 23878; I2=95%), and 2.010 (95% CI, 1922 to 2098, I2=97%), respectively. The mean GWE was 96.0 (95% CI, 95.6% to 96.5; I2=92%), and the mean GWW was 79.7% (95% CI, 68.8% to 90.7%; I2=90%) (Figure). Furthermore, age and gender did not significantly contribute to variations in normal values. No evidence of significant publication bias was observed in the funnel plots and the Egger test.

Conclusion

In this meta-analysis, we provide echocardiographic reference ranges for non-invasive indices of MW. These normal values should serve as a template for clinical and research use for this promising technology.

Funding Acknowledgement

Type of funding sources: None.

Obesity, not a high fat, high sucrose diet alone, induced glucose intolerance and cardiac dysfunction during pregnancy and postpartum

Cardiovascular disease is the leading cause of death in women during pregnancy and the postpartum period. Obesity is an independent risk factor for cardiovascular diseases. Nearly 60% of women of reproductive age are considered overweight or obese, cardiovascular disease morbidity and mortality continue to be pervasive. The objective of this study was to determine the effects of an obesogenic diet on the cardiometabolic health of dams during pregnancy and postpartum. Female mice were fed either a high-fat, high-sucrose diet (HFHS) or a refined control diet (CON) for 8 weeks before initiation of pregnancy and throughout the study period. Mice in the HFHS showed two distinct phenotypes, obesity-prone (HFHS/OP) and obesity resistance (HFHS/OR). Pre-pregnancy obesity (HFHS/OP) induced glucose intolerance before pregnancy and during postpartum. Systolic function indicated by the percent fractional shortening (%FS) was significantly decreased in the HFHS/OP at late pregnancy (vs. HFHS/OR) and weaning (vs. CON), but no differences were found at 6 weeks of postpartum among groups. No induction of pathological cardiac hypertrophy markers was found during postpartum. Plasma adiponectin was decreased while total cholesterol was increased in the HFHS/OP. Our results suggested that obesity, not the diet alone, negatively affected cardiac adaptation during pregnancy and postpartum.

Cerebrospinal Fluid Protein Concentration in Healthy Older Japanese Volunteers

The concentration of cerebrospinal fluid total protein (CSF-TP) is important for the diagnosis of neurological emergencies. Recently, some Western studies have shown that the current upper reference limit of CSF-TP is quite low for older patients. However, little is reported about the concentration of CSF-TP in the older Asian population. In this study, we retrospectively analyzed the CSF-TP concentrations in healthy older Japanese volunteers. CSF samples in 69 healthy Japanese volunteers (age range: 55–73 years) were collected by lumbar puncture, and the data of CSF were retrospectively analyzed. The mean (standard deviation) CSF-TP was 41.7 (12.3) mg/dL. The older group (≥65 years old) had higher CSF-TP concentration than the younger group (55–64 years old). The 2.5th percentile and 97.5th percentile of CSF-TP were estimated as 22.5 and 73.2 mg/dL, respectively, which were higher than the current reference range in Japan (10–40 mg/dL). Conclusions: The reference interval of CSF-TP in the older population should be reconsidered for the precise diagnosis of neurological emergencies.

Statistical Analysis of the Axillary Temperatures Measured by a Predictive Electronic Thermometer in Healthy Japanese Adults

Body temperature is important for diagnosing illnesses. However, its assessment is often a difficult task, considering the large individual differences. Although 37 °C has been the gold standard of body temperature for over a century, the temperature of modern people is reportedly decreasing year by year. However, a mean axillary temperature of 36.89 ± 0.34 °C reported in 1957 is still cited in Japan. To assess the measured axillary temperature appropriately, understanding its distribution in modern people is important. This study retrospectively analyzed 2454 axillary temperature measurement data of healthy Japanese adults in 2019 (age range, 20–79 years; 2258 males). Their mean temperature was 36.47 ± 0.28 °C (36.48 ± 0.27 °C in males and 36.35 ± 0.31 °C in females). Approximately 5% of the 20–39-year-old males had body temperature ≥37 °C, whereas 8% had a temperature ≥ 37 °C in the afternoon. However, none of the subjects aged ≥50 years reported body temperature ≥37 °C. In multivariable regression analysis, age, blood pressure, pulse rate, and measurement time of the day were associated with axillary temperature. Our data showed that the body temperature of modern Japanese adults was lower than that reported previously. When assessing body temperature, the age, blood pressure, pulse rate, and measurement time of the day should be considered.

SARS-CoV-2 Seroprevalence among Healthcare Workers in General Hospitals and Clinics in Japan

Coronavirus disease 2019 (COVID-19) has become a serious public health problem worldwide. In general, healthcare workers are considered to be at higher risk of COVID-19 infection. However, the prevalence of COVID-19 among healthcare workers in Japan is not well characterized. In this study, we aimed to examine the seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antibodies among 2160 healthcare workers in hospitals and clinics that are not designated to treat COVID-19 patients in Japan. The prevalence of SARS-CoV-2 immunoglobulin G was 1.2% in August and October 2020 (during and after the second wave of the pandemic in Japan), which is relatively higher than that in the general population in Japan (0.03-0.91%). Because of the higher risk of COVID-19 infection, healthcare workers should be the top priority for further social support and vaccination against SARS-CoV-2.

Clinical outcomes from antihypertensive therapies in moderate or severe aortic stenosis: a systematic review and meta-analysis

Background

Hypertension can negatively affect prognosis in moderate or severe aortic stenosis (AS), but antihypertensive therapy (AHT) is often avoided due to possible deleterious effects such as reduced coronary perfusion, left ventricular dysfunction and haemodynamic compromise.

Purpose

We systematically assessed and compared clinical outcomes in adults with moderate or severe AS treated with and without AHT.

Methods

Two independent reviewers performed screening, data extraction and risk of bias assessments from a systematic search of the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and grey literature without language restrictions up to September 9, 2019. Conflicts were resolved by the third reviewer. Outcomes of interest included mortality, left ventricular (LV) mass index, systolic blood pressure, diastolic blood pressure, and LV ejection fraction. Meta-analysis with pooled effect sizes using random-effects model, were estimated in R.

Results

Of 3,024 citations, 30 studies (26,224 patients) were included in the qualitative synthesis and 23 studies in meta-analysis. AHT was associated with favourable clinical outcomes and was well tolerated. AHT was associated with lower risk of all-cause mortality (Risk Ratio (RR)=0.69, 95% CI: 0.53–0.90, p=0.01, Figure). The effect size appears to differ with type of aortic valve replacement (AVR). AHT was associated with lower risk of acute kidney injury post-transcatheter AVR (RR=0.13, 95% CI:0.05–0.35, p=0.007). Favourable outcomes such as improved haemodynamic and echocardiographic parameters were demonstrated in some studies, but when pooled in meta-analysis, the differences did not reach statistical significance. However, heterogeneity was significant across studies.

Conclusion

This is the first systematic review and meta-analysis to demonstrate that AHT is safe and has a clinical benefit in patients with advanced stages of AS with significant improvement in survival or reduction in mortality without haemodynamic compromise. Further studies are required to determine the best AHT for patients with moderate or severe AS.

Forest plot of AHT effect on mortality.

Funding Acknowledgement

Type of funding source: None

Osteoprotective effect of green tea polyphenols and annatto-extracted tocotrienol in obese mice is associated with enhanced microbiome vitamin K2 biosynthetic pathways

The role of the gut microbiome in bone health has received significant attention in the past decade. We investigated the effects of green tea polyphenols (GTP) and annatto-extracted tocotrienols (AT) on bone properties and gut microbiome in obese mice. Male mice were assigned to a two (no AT vs. 400 mg/kg diet AT) × two (no GTP vs. 0.5% w/v GTP) factorial design, namely control, G, T, and G+T group respectively, for 14 weeks. The 4th lumbar vertebra (LV-4) and femur were harvested for bone microstructural analysis using μ-CT. Microbiome analysis using 16S rRNA gene sequencing of cecal feces was performed. AT increased bone volume at distal femur. GTP increased serum procollagen type 1 N-terminal propeptide concentration, bone volume at the distal femur and the LV-4, and trabecular number at distal femur; whereas GTP decreased trabecular separation at distal femur. Interactions between GTP and AT were observed in serum C-terminal telopeptide of type I collagen level (control>G=T=G+T) as well as the cortical bone area (control<G=T=G+T) and thickness (T≥G+T≥G≥control) at femur mid-diaphysis. Redundancy analysis showed a significant difference in the gut microbiome profile among different groups and the relative abundance of Akkermansia muciniphila, Clostridum saccharogumia, and Subdoligranulum variabile was increased in the GTP- and AT-supplemented groups. Functional profiling of the gut microbiome showed the combination of GTP and AT induced biosynthetic pathways for vitamin K₂. Our results suggest that GTP and AT supplementation benefits bone properties in obese mice through modifying gut microbiome composition and function.

Metabolic benefits of annatto-extracted tocotrienol on glucose homeostasis, inflammation, and gut microbiome

Emerging evidence suggests that the gut microbiome plays an important role in the pathophysiology of both obesity and type 2 diabetes mellitus. We previously reported that dietary annatto-extracted tocotrienol exerts beneficial effects by modulating inflammatory responses in mice fed a high-fat diet (HFD). The purpose of this study was to test the hypothesis that tocotrienol supplementation when combined with an HFD would result in an altered gut microbiota composition. For 14 weeks, forty-eight male C57BL/6J mice were assigned to 4 groups-low-fat diet, HFD, HFD supplemented with annatto-extracted tocotrienol at 800 mg/kg diet (AT), and HFD supplemented with metformin at 200 mg/kg diet. Glucose homeostasis was assessed by glucose and insulin tolerance tests, serum and pancreas insulin levels, and histological assessments of insulin and glucagon in pancreatic tissue. The concentrations of adipokines were measured in white adipose tissues. For the gut microbiome analysis, cecal content was collected, DNA was extracted, and 16S rRNA gene sequencing was performed. AT supplementation improved glucose homeostasis and lowered resistin, leptin, and interleukin-6 levels in white adipose tissue. Relative to the HFD group, AT-supplemented mice showed a decrease in the Firmicutes to Bacteroidetes ratio and had a lower abundance of Ruminococcus lactaris, Dorea longicatena, and Lachnospiraceae family. The relative abundance of Akkermansia muciniphila was increased in the AT group compared to the low-fat diet group. The association between the metabolic improvements and the identified bacterial taxa suggests a potential metabolic modulation caused by AT supplementation through the gut microbiota composition in mice fed an HFD.

Protein Content of Wheat by Near-Infrared Spectroscopy of Whole Grain: Collaborative Study

A collaborative study was performed to assess accuracy, repeatability, and reproducibility of a nearinfrared (near-IR) method for determining crude protein content (PC) of whole-grain wheat. Four types of commercially available near-IR instruments, representing various combinations of wavelength region, mode of energy capture, method of energy dispersion, and treatment of spectral data, were used. Eight, 9,10, and 11 collaborators were involved, the exact number depending on instrument type. All collaborators received 22 samples of whole-grain hard red winter (HRW) wheat. They were furnished reference PCs (i.e., protein concentrations, w/w) corrected to a 12% moisture basis for instrument standardization. AOAC Method 990.03— combustion analysis—was the reference procedure. Standardization consisted of performing one of the following treatments to the instrument manufacturer's (or federal agency's) PC equation: (1) bias correction, (2) slope and intercept correction, or (3) recalibration with inclusion of standardization sample spectra. Standardized equations were then applied to a test set of 12 unknown HRW wheat sample spectra, with 2 samples blindly duplicated. The PCs of test samples ranged from 9 to 16%. Near-IR predictions were compared with reference measurements. Averaged within instrument type, root mean square of differences were 0.22, 0.24, 0.25, and 0.26% PC, depending on instrument. Corrected for bias within the test set, standard errors became 0.22, 0.18, 0.21, and 0.24% PC, respectively. These values were approximately twice the estimated lower limit for error (representing sample inhomogeneity). Overall repeatability relative standard deviation (RSD,) values were 0.92, 0.36, 0.42, and 0.74%, respectively. Overall reproducibility relative standard deviation (RSDR) values were 1.15, 0.61,1.53, and 1.38%. Such values for within-laboratory and between-laboratory variations of the near- IR methods were equivalent to values reported for the combustion method (990.03) for wheat. An inhouse study that examined all 6 U.S. wheat classes with one of the 4 instrument types produced repeatability and reproducibility values similar to those of the collaborative study, suggesting that the near-IR technique may be applied to red, white, hard, soft, and durum wheats. The near-IR method for determination of PC of whole-grain wheat has been adopted First Action (997.06) by AOAC INTERNATIONAL.

Evaluation of vancomycin target trough attainment with published dosing regimens in the neonatal intensive care unit population

BACKGROUND

Study aims to evaluate whether vancomycin dosing from published dosing algorithms correlate with the attainment of target troughs of 10 to 20 mg/L.

METHODS

NICU patients who received minimum three doses of vancomycin and had a trough level met inclusion criteria. Dosing information was retrospectively evaluated to determine which published dosing regimen was followed. Dosing algorithms used were matched to NeoFax/Harriet Lane, renal-function directed dosing, and weight-directed dosing, in which the latter two can be found in Pediatric and Neonatal Lexi-Drugs. Primary outcome was percentage of troughs within therapeutic (10 to 20 mg/L) and subtherapeutic (less than 10 mg/L) levels.

RESULTS

Of 97 troughs evaluated, NeoFax/Harriet Lane accounted for 86.6%, renal-function directed accounted for 5.1%, and weight-directed dosing accounted for 18.5% of dosing algorithms. NeoFax/Harriet Lane, renal-function directed, and weight-directed dosing attained therapeutic levels between 10 to 20 mg/L at a rate of 60.7%, 60%, and 50% of the time, respectively. With respect to initiation of therapy, a higher dose of 15 mg/kg versus 10 mg/kg attained therapeutic levels (p < 0.001; OR 11.22; 95% CI, 3.96 to 31.81), while a serum creatinine value below 0.5 mg/dL attained subtherapeutic levels (p = 0.028; OR 0.068; 95% CI, 0.006 to 0.74).

CONCLUSIONS

NeoFax, Harriet Lane, and renal-directed dosing from Pediatric and Neonatal Lexi-Drugs achieved target troughs within the 10 to 20 mg/L range more often than weight-directed dosing from Pediatric and Neonatal Lexi-Drugs. Initiating therapy at a higher dose and patient serum creatinine value above 0.5 mg/dL were factors significantly associated with a 10 to 20 mg/L range.

Effect of Geranylgeraniol and Green Tea Polyphenols on High-fat-diet-induced Bone Deterioration in Male B6 Mice (P06-025-19)

Objectives

To investigate the combined effects of geranylgeraniol (GG, a 20-carbon isoprenoid found in fruits, vegetables, and grains) and green tea polyphenols (GTP, extracted from green tea) on high-fat-diet (HFD) induced bone deterioration in obese male mice. Our previous studies demonstrated that GG or GTP, when supplemented separately, was beneficial to the bone health of obese animals. Therefore, we hypothesized that GG combined with GTP would improve bone structure of obese mice fed a HFD.

Methods

Forty-eight male C57BL/6 J mice were assigned to 4 groups (n = 12/group) in a 2 (no GG vs. GG) × 2 (no GTP vs. GTP) factorial design: HFD, HFD + GG (400 mg GG/kg diet), HFD + GTP [0.5% (w/v) in drinking water], and HFD + GG + GTP. Animals were fed the respective diet ad libitum for 14 weeks.

Results

GTP supplementation, not GG, resulted in lower final body weight and greater fasting serum insulin concentrations. Supplementation of GG or GTP (separate, but not together) lowered blood glucose concentrations at 120 min. A decreased area under the curve of glucose tolerance tests and insulin tolerance test in the HFD + GG + GTP group was observed suggesting improved glucose clearance and insulin sensitivity, but no interaction was found between GG and GTP. Neither GG nor GTP affected serum concentrations of insulin or procollagen type I intact N-terminal (a bone formation marker). There was an interaction effect for serum concentrations of collagen type 1 cross-linked C-telopeptide (CTX, a bone resorption marker), resulting in HFD + GG + GTP being the lowest. Neither GG nor GTP supplementation affected the total area, bone area, and cortical thickness at the femur midshaft or the bone volume/total volume at the lumbar vertebrae. GG supplementation increased trabecular number and decreased trabecular separation at the lumbar vertebrae. GTP supplementation increased trabecular thickness at lumbar vertebrae. HFD + GG produced the greatest connectivity density and the lowest structure model index.

Conclusions

This study suggests a beneficial role of supplementing GG with GTP in bone health of obese animals.

Funding Sources

The study was supported by American River Nutrition to CLS and USDA ARS Project no. 3062-51,000-053-00D.

Strength training attenuates post-infarct cardiac dysfunction and remodeling

Post-myocardial infarction (MI) exercise has been employed to improve cardiac function. However, most studies have focused on endurance training (Et). Although Et has been reported to preserve cardiac function, evidence suggests that Et increases left ventricle (LV) interior dimensions as a result of albumin-induced plasma expansion. In contrast, strength training (St) induces concentric cardiac hypertrophy and improved cardiac function without causing ventricular dilation. Therefore, the purpose of this study was to investigate the effects of St on cardiac function and remodeling in rats with MI. MI was surgically induced in 7-week-old rats via ligation of the coronary artery. Survivors were assigned to two experimental groups, MI-Sed (No exercise; n = 9), MI-St (St; n = 10), with a Sham group (no MI, no St; n = 9). MI-St rats began training 1-week post-MI by climbing a ladder with weights for 10 weeks. Echocardiographic measurements were performed prior to, and following exercise training, while in vivo LV hemodynamic analysis was conducted at the end of the experimental period. Our data revealed that St induced shortening of the LV end-diastolic dimension in the MI-St group compared with the MI-Sed group (P < 0.05). The peak velocities of contraction (+ dP/dt max) and relaxation (- dP/dt max) were significantly greater in the MI-St group than the MI-Sed group (P < 0.05). These training effects contributed to the improved fractional shortening (%FS). Our results demonstrate that St may be beneficial for post-MI by attenuating LV dilation and concomitant cardiac dysfunction associated with MI.

Pregnancy late in rodent life has detrimental effects on the heart

During pregnancy, the heart undergoes significant and numerous changes, including hypertrophy, that are usually described as physiological and reversible. Two aspects of the cardiac response to pregnancy are relatively understudied: advanced maternal age and multiple pregnancies (multiparity). Repeated breeder (RB) mice that have undergone five to seven consecutive pregnancies were euthanized 21 days after the weaning of their last pups and compared with age-matched primiparous, one-time pregnant (O1P) mice. The ages of the older mouse groups were similar (12 ± 1 mo). Pregnancy at a later age resulted in reduced fertility (40%); resorption was 29%, maternal mortality was 10%, and mortality of the pups was 17%. Contractile function as indicated by percent fractional shortening was significantly decreased in O1P and RB groups compared with the old nonpregnant control (ONP) group. There was no pathological induction of the fetal program of gene expression, with the exception of β-myosin heavy chain mRNA, which was induced in O1P compared with ONP mice ( P < 0.05) but not in RB mice. MicroRNA-208a was significantly increased in O1P compared with ONP mice ( P < 0.05) but significantly decreased in RB compared with ONP mice ( P < 0.05). mRNA of genes regulating angiogenesis (i.e., vascular endothelial growth factor-A) were significantly downregulated, whereas proinflammatory genes [i.e., interleukin-6, chemokine (C-C motif) ligand 2, and Cd36] were significantly upregulated in O1P ( P < 0.05) but not in RB mice. Overall, our results suggest that rather than multiparity, pregnancy in advanced age is a much more stressful event in both pregnant dams and fetuses, as evidenced by increased mortality, lower fertility, downregulation of angiogenesis, upregulation of inflammation, and cardiac dysfunction. NEW & NOTEWORTHY Pregnancy in older mice significantly decreases cardiac function, although repeated breeder mice demonstrated increased wall hypertrophy and dilated chamber size compared with one-time pregnant mice. Interestingly, many of the molecular changes were altered in one-time pregnant mice but not in repeated breeder mice, which may contribute to adverse pregnancy outcomes in a first pregnancy at a later age.