Pathways in Skeletal Muscle: Protein Signaling and Insulin Sensitivity after Exercise Training and Weight Loss Interventions in Middle-Aged and Older Adults.

Aging and obesity contribute to insulin resistance with skeletal muscle being critically important for maintaining whole-body glucose homeostasis. Both exercise and weight loss are lifestyle interventions that can affect glucose metabolism. The purpose of this study was to examine the effects of a six-month trial of aerobic exercise training or weight loss on signaling pathways in skeletal muscle in the basal condition and during hyperinsulinemia during a glucose clamp in middle-aged and older adults. Overweight and obese men and women aged 50-70 years were randomly allocated and completed six months of either weight loss (WL) (n = 18) or 3x/week aerobic exercise training (AEX) (n = 17). WL resulted in 10% weight loss and AEX increased maximal oxygen consumption (VO2max) (both p < 0.001). Insulin sensitivity (hyperinsulinemic-euglycemic 80 mU·m-2·min-1 clamp) increased in WL and AEX (both p < 0.01). In vivo insulin stimulation increased phosphorylation/total protein ratio (P/T) of protein kinase B (Akt), glycogen synthase kinase 3 beta (GSK-ß3), 70 kDa ribosomal protein S6 kinase (p70S6k), insulin receptor substrate 1 (IRS-1), and insulin receptor (IR) expression (all p < 0.05) but not P/T extracellular regulated kinase ½ (ERK1/2), c-jun N-terminal kinases (JNK), p38 mitogen-activated protein kinases (p38), or insulin-like growth factor 1 receptor (IGF-1R). There were differences between WL and AEX in the change in basal Akt P/T (p = 0.05), GSK-3ß P/T ratio (p < 0.01), p70S6k (p < 0.001), ERK1/2 (p = 0.01) P/T ratio but not p38, JNK, IRS-1, and IGF-1R P/T ratios. There was a difference between WL and AEX in the insulin stimulation changes in GSK3 which increased more after WL than AEX (p < 0.05). In the total group, changes in M were associated with changes in basal total GSK-3ß and basal total p70Sk as well as insulin stimulation of total p70Sk. Protein signaling in skeletal muscle provides insight as to mechanisms for improvements in insulin sensitivity in aging and obesity.

Poly is more effective than monounsaturated fat for dietary management in the metabolic syndrome: The muffin study.

BACKGROUND: The metabolic syndrome (MetS) is highly prevalent and associated with an increased risk for type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). Lifestyle recommendations to treat MetS often include the replacement of saturated fats (SFAs) and monosaccharides with unsaturated fat. However, it is unclear whether metabolic parameters will improve more when the saturated fat in American Heart Association (AHA) diets is replaced with higher concentrations of monounsaturated or polyunsaturated fatty acids (MUFA or PUFA). OBJECTIVE: To test the hypothesis that an AHA diet enriched in MUFA improves lipoprotein lipids, insulin resistance, inflammation, and endothelial function to a greater extent than a diet enriched in PUFA in middle-aged men and women with MetS. METHODS: A prospective, open-label, parallel group design with randomization to a hypocaloric MUFA or PUFA-enriched diet after weight stabilization on an AHA step I diet. Participants consumed 3 MUFA-enriched or PUFA-enriched muffins daily with additional supplementation as required to ensure 25%-50% increases in dietary fat intake from these sources at the expense of SFA and the opposing unsaturated fat. Changes in MetS components were measured at baseline and after 6 months of dietary intervention. RESULTS: Thirty-nine participants (mean age, 60.8 years; 79% African-American, 60% women) with MetS completed the 6-month study. Compared to baseline, assignment to either MUFA (n = 23) or PUFA (n = 16) both were associated with weight loss (MUFA: -2.3 ± 1 kg, P = .06; PUFA: -4.6 ± 2 kg; P = .002), but PUFA was also associated with reductions in triglycerides (TG) (-30 ± 18 mg/dL, P = .02), systolic blood pressure (BP) (-7 ± 3 mm Hg, P = .01), diastolic BP (DBP) (-4 ± 2 mm Hg, P = .01) and improved flow mediated dilation (FMD) (7.1% ± 1.8% vs 13.6% ± 2%, absolute increase; P = .0001). When compared to MUFA treatment, PUFA intervention was associated with reduced TG (P = .04) and DBP (P = .07) as well as increased FMD (P = .04) even after adjustment for changes in weight. There was no effect on total cholesterol, low-density lipoprotein cholesterol, glucose, high-sensitivity C-reactive protein (hs-CRP), or other inflammatory proteins. Overall, 25% (4 of 16) assigned to PUFA and 13% (3 of 23) to MUFA converted to non-MetS status. CONCLUSION: Substitution of SFA with PUFA in patients with MetS is associated with greater reductions in TG and improvement in endothelial function than MUFA that is independent of weight loss. These preliminary findings raise the possibility that PUFA may be the unsaturated fat of choice to reduce cardiometabolic risk in patients with MetS.

Pediatric epilepsy following neonatal seizures symptomatic of stroke.

BACKGROUND: Neonatal seizures are a risk factor for later epilepsy and their etiology is known to be implicated in the outcome but, little is known about this issue in the subgroup of seizures symptomatic of perinatal arterial ischemic stroke. The aim of this study was to describe the long term risk of epilepsy after electroencephalographic confirmed neonatal seizures symptomatic of perinatal arterial ischemic stroke. DESIGN/SUBJECT: Fifty-five patients with electroclinical ictal data, vascular territory confirmed by neuroimaging and a minimum follow up of 3.5 years were identified from a multi-centre prospective neonatal seizures registry. Primary outcome was occurrence of post-neonatal epilepsy. The association of outcome with family history of epilepsy, gender, location of the infarct, neonatal clinical and electroencephalogram data were also studied. RESULTS: During a mean follow up of 8 years and 5 months, 16.4% of the patients developed post neonatal epilepsy. The mean age at first post neonatal seizure was 4 years and 2 months (range 1-10 years and 6 months). Location of the infarct was the only statistically significant risk factor (p=0.001); epilepsy was more represented in males but the difference was not statistically significant. CONCLUSIONS: Neonatal seizures symptomatic of perinatal arterial ischemic stroke had lower risk and later onset of post-neonatal epilepsy, compared to seizures described in the setting of other perinatal brain insults. Our data have implications for counseling to the family at discharge from neonatal intensive care unit.

Benign myoclonic epilepsy in infancy (BMEI): a longitudinal electroclinical study of 22 cases.

PURPOSE: Benign myoclonic epilepsy in infancy (BMEI) is a nosologically well-defined entity, characterized by myoclonic seizures (MS) in normal children younger than 3 years and by a good long term prognosis. In some cases the seizures are reflex. We studied 22 cases to better define the electroclinical semeiology and evolution of the disorder. METHODS: Serial electroclinical and neuropsychological assessments, both during wakefulness and during sleep, were performed in 22 otherwise healthy children with spontaneous (17) or reflex (5) MS, recorded by video-EEG-polygraphy since clinical onset. RESULTS: Seizure onset was between 3 months and 4 years 10 months (50% during first year, 86% before the third year); in reflex cases onset, was earlier than the 14th month. MS recurred during wakefulness and slow sleep in all cases and during REM sleep in reflex cases. MS and related EEG discharges were synchronous or asynchronous. Often ictal EEG discharges were limited to the rolandic and vertex regions (falsely focal paroxysms). Several seizures were subtle and could have escaped recognition. Unusually frequent sleep startles were recorded mostly in reflex cases. MS were well controlled by treatment. At follow-up, between ages 3 and 19 years, four patients had occasional seizures; two had cognitive impairment and three had learning difficulties. No other seizures or cognitive deficits were observed in reflex cases. CONCLUSIONS: Seizures associated with BMEI are rarely truly generalized and are often so subtle and related to falsely focal paroxysms that their frequency can be underestimated. The reflex form is a well-defined variant with an early onset, peculiar electroclinical features, and a good prognosis.