Possible Hormone Predictors of Physical Performance in Adolescent Team Sport Athletes.

Martin, AC, Heazlewood, IT, Kitic, CM, Lys, I, and Johnson, L. Possible hormone predictors of physical performance in adolescent team sport athletes. J Strength Cond Res 33(2): 417-425, 2019-The research aim of this study was to determine possible hormone predictors of physical performance in adolescent team sport athletes. Saliva samples were collected immediately before performance testing sessions from 114 state squad athletes (77 males, 37 females) participating in either Australian football, basketball, hockey, or netball. Participants completed tests of aerobic and anaerobic capacity, agility, power, and speed. Samples were collected over 22 months at quarterly, six-monthly, and/or yearly intervals depending on the testing schedule of the athlete. Saliva was analyzed for testosterone (T), cortisol (C), estradiol (E), and progesterone (P) levels. A strong negative correlation existed between multistage fitness test performance and T:E ratio (r = -0.76, p = 0.01) in females not taking oral contraceptives, and a strong positive correlation existed between repeat agility total time and estradiol levels (r = -0.71, p = 0.001) in females taking oral contraceptives. In males, strong negative correlations were evident for individual changes in planned agility time and estradiol levels (r = 0.87, p = 0.02), and countermovement jump (CMJ) height and T:C (r = -0.88, p = 0.01). In females taking oral contraceptives, a strong positive correlation was noted between individual change in yo-yo intermittent recovery test performance and T:E (r = 0.74, p = 0.01) and a strong negative correlation was noted between 20-m speed and T:P (r = 0.73, p = 0.01). In females not taking oral contraceptives, a strong negative correlation was found between individual change in CMJ height and T:P (r = -0.72, p = 0.02). The findings show that in adolescent team sport athletes, the P:E, T:E, and the T:P ratios are important predictors of performance in tests of physical capacity. The findings also indicate that estradiol and progesterone have a predictive function in the physical performance of adolescent male team sport athletes.

The complete mitogenome of the New Zealand freshwater crayfish Paranephrops planifrons White 1842 (Crustacea: Decapoda: Parastacidae).

The mitogenome of Paranephrops planifrons, was obtained by next generation sequencing. This crayfish has a mitochondrial genome of 16,174 base pairs with 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs (tRNA), and a non-coding AT-rich region of 771 bp. The P. planifrons nucleotide composition is: 33.63% for T, 21.92% for C, 34.46% for A, and 9.98% for G and has a 68.09% AT bias. While the mitogenome gene order for this species is consistent with aspects of the highly distinctive parastacid crayfish mitogenome gene arrangement, it has a novel gene order involving the rearrangements of a protein coding and several tRNA genes.

Multi-omic integrated networks connect DNA methylation and miRNA with skeletal muscle plasticity to chronic exercise in Type 2 diabetic obesity.

Epigenomic regulation of the transcriptome by DNA methylation and posttranscriptional gene silencing by miRNAs are potential environmental modulators of skeletal muscle plasticity to chronic exercise in healthy and diseased populations. We utilized transcriptome networks to connect exercise-induced differential methylation and miRNA with functional skeletal muscle plasticity. Biopsies of the vastus lateralis were collected from middle-aged Polynesian men and women with morbid obesity (44 kg/m(2) ± 10) and Type 2 diabetes before and following 16 wk of resistance (n = 9) or endurance training (n = 8). Longitudinal transcriptome, methylome, and microRNA (miRNA) responses were obtained via microarray, filtered by novel effect-size based false discovery rate probe selection preceding bioinformatic interrogation. Metabolic and microvascular transcriptome topology dominated the network landscape following endurance exercise. Lipid and glucose metabolism modules were connected to: microRNA (miR)-29a; promoter region hypomethylation of nuclear receptor factor (NRF1) and fatty acid transporter (SLC27A4), and hypermethylation of fatty acid synthase, and to exon hypomethylation of 6-phosphofructo-2-kinase and Ser/Thr protein kinase. Directional change in the endurance networks was validated by lower intramyocellular lipid, increased capillarity, GLUT4, hexokinase, and mitochondrial enzyme activity and proteome. Resistance training also lowered lipid and increased enzyme activity and caused GLUT4 promoter hypomethylation; however, training was inconsequential to GLUT4, capillarity, and metabolic transcriptome. miR-195 connected to negative regulation of vascular development. To conclude, integrated molecular network modelling revealed differential DNA methylation and miRNA expression changes occur in skeletal muscle in response to chronic exercise training that are most pronounced with endurance training and topographically associated with functional metabolic and microvascular plasticity relevant to diabetes rehabilitation.

Degradation of [Dha(7)]MC-LR by a Microcystin Degrading Bacterium Isolated from Lake Rotoiti, New Zealand.

For the first time a microcystin-degrading bacterium (NV-3 isolate) has been isolated and characterized from a NZ lake. Cyanobacterial blooms in New Zealand (NZ) waters contain microcystin (MC) hepatotoxins at concentrations which are a risk to animal and human health. Degradation of MCs by naturally occurring bacteria is an attractive bioremediation option for removing MCs from drinking and recreational water sources. The NV-3 isolate was identified by 16S rRNA sequence analysis and found to have 100% nucleotide sequence homology with the Sphingomonas MC-degrading bacterial strain MD-1 from Japan. The NV-3 isolate (concentration of 1.0 × 10(8) CFU/mL) at 30°C degraded a mixture of [Dha(7)]MC-LR and MC-LR (concentration 25 µ g/mL) at a maximum rate of 8.33 µ g/mL/day. The intermediate by-products of [Dha(7)]MC-LR degradation were detected and similar to MC-LR degradation by-products. The presence of three genes (mlrA, mlrB, and mlrC), that encode three enzymes involved in the degradation of MC-LR, were identified in the NV-3 isolate. This study confirmed that degradation of [Dha(7)]MC-LR by the Sphingomonas isolate NV-3 occurred by a similar mechanism previously described for MC-LR by Sphingomonas strain MJ-PV (ACM-3962). This has important implications for potential bioremediation of toxic blooms containing a variety of MCs in NZ waters.

Exercise improves quality of life in indigenous Polynesian peoples with type 2 diabetes and visceral obesity.

BACKGROUND: To evaluate the differential effect of 2, group-based exercise modalities on quality of life (QoL) in indigenous Polynesian peoples with type 2 diabetes (T2DM) and visceral obesity. METHODS: Participants were randomized to resistance training or aerobic training performed 3 times per for 16 weeks. The Short-Form 36 was administered at baseline and post intervention to assess 8 domains and physical and mental component scales (PCS and MCS) of QoL. RESULTS: With the exception of Mental Health and MCS, all scores were lower at baseline than general population norms. Significant improvements were documented in several QoL scores in each group post intervention. No group x time interactions were noted. Pooled analyses of the total cohort indicated significantly improved Physical Functioning, Role-Physical, Bodily Pain, General Health, Vitality, Role-Emotional, PCS and MCS. Adaptation ranged from 5%-22%, and demonstrated a moderate-to-large effect (Cohen's d = 0.64-1.29). All measures of QoL increased to near equivalent, or greater than general norms. CONCLUSION: Exercise, regardless of specific modality, can improve many aspects of QoL in this population. Robust trials are required to investigate factors mediating improvements in QoL, and create greater advocacy for exercise as a QoL intervention in this and other indigenous populations with T2DM.

Exercise intervention in New Zealand Polynesian peoples with type 2 diabetes: Cultural considerations and clinical trial recommendations.

The Maori and Pacific Islands peoples of New Zealand suffer a greater burden of type 2 diabetes mellitus (T2DM) and associated comorbidities than their European counterparts. Empirical evidence supports the clinical application of aerobic and resistance training for effective diabetes management and potential remission, but few studies have investigated the effectiveness of these interventions in specific ethnic cohorts. We recently conducted the first trial to investigate the effect of prescribed exercise training in Polynesian people with T2DM. This article presents the cultural considerations undertaken to successfully implement the study. The research procedures were accepted and approved by cultural liaisons and potential participants. The approved methodology involved a trial evaluating and comparing the effects of two, 16-week exercise regimens (i.e. aerobic training and resistance training) on glycosylated haemoglobin (HbA1c), related diabetes markers (i.e. insulin resistance, blood lipids, relevant cytokines and anthropometric and hemodynamic indices) and health-related quality of life. Future exercise-related research or implementation strategies in this cohort should focus on cultural awareness and techniques to enhance participation and compliance. Our approach to cultural consultation could be considered by researchers undertaking trials in this and other ethnic populations suffering an extreme burden of T2DM, including indigenous Australians and Americans.

South Pacific Islanders resist type 2 diabetes: comparison of aerobic and resistance training.

The purpose of this study was to evaluate the effectiveness of two exercise modalities for improving glycosylated hemoglobin (HbA1c) and associated clinical outcomes in Polynesian adults diagnosed with type 2 diabetes and visceral obesity. Twenty-six adults were randomized to receive resistance training or aerobic training, 3×/week, for 16 weeks. Dependent variables collected before and after intervention included: diabetes markers including HbA1c, blood lipids, relevant cytokines (C-reactive protein, adiponectin), and anthropometric and hemodynamic indices. Eighteen participants (72% female; age: 49.3 ± 5.3 years; waist circumference: 128.7 ± 18.7 cm) completed the intervention and follow-up assessments. Body mass index in the whole cohort at baseline indicated Class III (morbid) obesity (43.8 ± 9.5 kg/m(2)). Compliance to training was 73 ± 19 and 67 ± 18% in the aerobic and resistance training groups, respectively. HbA1c remained elevated in both groups after training. Aerobic training reduced systolic and diastolic blood pressure and increased serum triglycerides (all P < 0.05). No other exercise-induced adaptations were noted within or between groups. Post hoc analysis using pooled data indicated that higher adherence to training (≥75% attendance, n = 8) significantly reduced waist circumference (P < 0.001) and tended to reduce body weight and fasting insulin (all P ≤ 0.11) versus lower adherence (<75% attendance, n = 10). In conclusion, this study did not demonstrate an improvement in HbA1c with exercise in morbidly obese Polynesian people. Future investigations involving exercise regimens that are more practicable and which involve greater frequency and duration of training may be required to induce significant and clinically meaningful adaptations in this unique diabetes population.