Does climacteric status impact regulation of the autonomic nervous system at the age of 46 years?

OBJECTIVE: To investigate whether an earlier-onset climacteric phase is associated with autonomic imbalance at the age of 46 years. METHODS: This cross-sectional birth cohort study included 2661 women aged 46 years. Participants were divided into climacteric (n = 359) and preclimacteric (n = 2302) groups based on menstrual history and follicle stimulating hormone values. The mean heart rate (HR), low-frequency (LF) power, high-frequency (HF) power and LF/HF ratio were analyzed from heart rate variability recordings. The variables were compared between the groups using multivariable linear regression models, including body mass index, smoking and physical activity. The effects of hormone therapy and hot flashes on autonomic function were evaluated in sub-analyses. RESULTS: Climacteric women had a lower mean HR in seated (71.9 ± 10.5 vs. 72.6 ± 10.4 bpm, p = 0.015) and standing (81.2 ± 12.8 vs. 83.6 ± 12.1 bpm, p = 0.002) positions compared to preclimacteric women, and the differences remained significant after the adjustments. In the sub-analyses, more frequent hot flashes were associated with a lower LF power and LF/HF ratio in the sitting position. CONCLUSIONS: The present study suggested an association between greater parasympathetic activation in women with more advanced climacteric status at the age of 46 years.

Effects of dry period energy intake on insulin resistance, metabolic adaptation, and production responses in transition dairy cows on grass silage-based diets.

High energy intake in the dry period has reportedly had adverse effects on mobilization of body reserves, dry matter intake, and productivity of dairy cows. We investigated whether grass silage (GS) fed ad libitum (high energy intake, HEI; 141% of daily metabolizable energy requirements) in an 8-wk dry period affects metabolic adaptation-specifically, peripheral insulin resistance-compared with a total mixed ration consisting of GS, wheat straw, and rapeseed meal (55/40/5%; controlled energy intake, CEI; 108% of metabolizable energy/d) fed ad libitum. Multiparous Ayrshire dairy cows (n = 16) were used in a randomized complete block design until 8 wk after parturition. Commercial concentrates were fed 1 and 2 kg/d during the last 10 to 6 and 5 to 0 d before the expected calving date, respectively. Postpartum, a similar lactation diet with ad libitum access to GS and increasing concentrate allowance (maximum of 16 kg/d) was offered to all. The HEI group gained more body weight and had higher plasma insulin, glucose, and ß-hydroxybutyrate concentrations than the CEI group prepartum. Postpartal plasma glucose tended to be higher and milk yield was greater from wk 5 onward for HEI compared with CEI cows. An intravenous glucose tolerance test (IVGTT) was performed at -13 ± 5 d and 9 ± 1 d relative to calving. The HEI cows had greater insulin response to glucose load and smaller area under the response curve for glucose than CEI cows in prepartal IVGTT. Thus, compensatory insulin secretion adapted to changes in insulin sensitivity of the peripheral tissues, preserving glucose tolerance of HEI cows. Higher insulin levels were needed in HEI cows than in CEI cows to elicit a similar decrement of nonesterified fatty acid concentration in prepartal IVGTT, suggesting reduced inhibition of lipolysis by insulin in HEI cows before parturition. In conclusion, high energy intake of moderately digestible GS with low concentrate feeding in the close-up dry period did not have adverse effects on metabolic adaptation, insulin sensitivity, and body mobilization after parturition. Instead, this feeding regimen was more beneficial to early-lactation performance than GS-based total mixed ration diluted with wheat straw.

[Control of cardiovascular risk factors in coronary patients one year after cardiac rehabilitation]. / Contrôle des facteurs de risque chez les patients coronariens un an après une réadaptation cardiaque.

OBJECTIVE: To assess risk factors monitoring in coronary patients one year after cardiac rehabilitation. METHOD: From 2015 to 2015, cardiac morbidity, total mortality and risk factors data were collected from a 4-week ambulatory cardiac rehabilitation program with a control one year later and were compared with the results of Euroaspire and Reach studies. RESULTS: Out of 1091 (87%) coronary patients, 746 (68%) were re-examined 12months later (aged 60years (ranging from 20 to 85years), 15% women, 44% hypertensive, 36% smokers, 17% diabetics, 74% with dyslipidemia). At the end of the program, management of CV risk factors was improved (BP ≤ 140/90mmHg and BMI > 30: 80 and 20% vs 65 and 25% at the beginning of the program; LDL < 0.7g/L: 42% and smoking: 4% vs 18% when hospitalized for their cardiac event). Unfortunately, this benefit decreased significantly at one year (BP ≤ 140/90mmHg: 63%, LDL < 0.7g/L: 27%; smoking: 6%) but it remains better than in Euroaspire IV study: 57, 20 et 16% respectively). While 54% had insufficient physical activity before cardiac rehabilitation, they were only 23% at 1-year vs 60% in Euroaspire study. We reported a total mortality of 0.6% vs 2.9% in Reach study and 12% cardiac hospitalization (53% for a new coronary event). CONCLUSION: Participation of coronary patients in a cardiac rehabilitation program significantly improves management of CV risk factors, morbidity and mortality. However, the control obtained at the end of the program decreases at one year.

Effects of dietary energy allowance and decline in dry matter intake during the dry period on responses to glucose and insulin in transition dairy cows.

We assessed whether high energy intake during the early dry period [144% of metabolizable energy (ME) requirements/d] followed by a gradual restriction of energy intake in the close-up dry period (119% of ME/d; HEI) impaired whole-body insulin sensitivity compared with a controlled energy intake (100% of ME/d; CEI) throughout the 6-wk dry period. Multiparous Ayrshire dairy cows (n = 16) were blocked by body weight, body condition score, and expected date of parturition and were used in a randomized complete block design until 10 d after parturition. Cows were fed either HEI or CEI diets based on grass silage during the first 3 wk of the dry period and grass silage supplemented with a commercial concentrate (30% of ME intake) during the final 3 wk of gestation. After calving, all cows were fed grass silage ad libitum and an increasing amount of commercial concentrate (maximum 9 kg at d 10 postpartum). Intravenous glucose tolerance tests (IVGTT) and intravenous insulin challenges were performed -10 ± 5 d (n = 15) and +10 ± 1 d (n = 14) relative to parturition. Following glucose injection, we did not find any treatment effects on glucose and insulin responses. The prepartal nonesterified fatty acid (NEFA) response of the HEI group was blunted, basal NEFA and the decrement of NEFA were smaller, and the area under the response curve (AUC) of NEFA was less negative in HEI cows than in CEI cows. The NEFA response reversed after parturition; the NEFA AUC of the HEI group was more negative than that of the CEI group. We did not find similar responses after insulin injection. Across the treatments, NEFA AUC correlated strongly with the basal NEFA concentration during the IVGTT pre- and postpartum. Calculated and model-based indices characterizing the overall glucose tolerance and ß-cell function and the insulin sensitivity were higher after parturition than during the dry period. Consistent with the lower basal insulin, the acute insulin release after the glucose infusion was smaller in postpartal IVGTT than in prepartal IVGTT. The results suggest that whole-body insulin sensitivity of the cows increased after parturition. However, the role of peripheral insulin sensitivity in the regulation of glucose partitioning seems to be minor relative to the major change in insulin secretion and clearance during the periparturient period.

Prepartal dietary energy alters transcriptional adaptations of the liver and subcutaneous adipose tissue of dairy cows during the transition period.

Overfeeding during the dry period may predispose cows to increased insulin resistance (IR) with enhanced postpartum lipolysis. We studied gene expression in the liver and subcutaneous adipose tissue (SAT) of 16 Finnish Ayrshire dairy cows fed either a controlled energy diet [Con, 99 MJ/day metabolizable energy (ME)] during the last 6 wk of the dry period or high-energy diet (High, 141 MJ/day ME) for the first 3 wk and then gradually decreasing energy allowance during 3 wk to 99 MJ/day ME before the expected parturition. Tissue biopsies were collected at -10, 1, and 9 days, and blood samples at -10, 1, and 7 days relative to parturition. Overfed cows had greater dry matter, crude protein, and ME intakes and ME balance before parturition. Daily milk yield, live weight, and body condition score were not different between treatments. The High cows tended to have greater plasma insulin and lower glucagon/insulin ratio compared with Con cows. No differences in circulating glucose, glucagon, nonesterified fatty acids and ß-hydroxybutyrate concentrations, and hepatic triglyceride contents were observed between treatments. Overfeeding compared with Con resulted in lower CPT1A and PCK1 and a tendency for lower G6PC and PC expression in the liver. The High group tended to have lower RETN expression in SAT than Con. No other effects of overfeeding on the expression of genes related to IR in SAT were observed. In conclusion, overfeeding energy prepartum may have compromised hepatic gluconeogenic capacity and slightly affected IR in SAT based on gene expression.

Effects of abomasal infusion of tallow or camelina oil on responses to glucose and insulin in dairy cows during late pregnancy.

Late pregnancy is associated with moderate insulin resistance in ruminants. Reduced suppression of lipolysis by insulin facilitates mobilization of nonesterified fatty acids (NEFA) from adipose tissue, resulting in elevated plasma NEFA concentrations. Decrease in dry matter intake (DMI) before parturition leads to accelerated lipomobilization and increases plasma NEFA, which may further impair insulin sensitivity. The aim of the study was to evaluate the effects of elevation of plasma NEFA concentration by abomasal infusions tallow (TAL) or camelina oil (CAM) on whole-body responses to exogenous glucose and insulin. We further assessed whether CAM, rich in C18:3n-3, enhances whole-body insulin sensitivity compared with TAL. Six late-pregnant, second-parity, rumen-cannulated dry Ayrshire dairy cows fed grass silage to meet 95% of metabolizable energy requirements were used in a replicated 3 × 3 Latin square with 5-d periods and 5 recovery days between each period. Treatments consisted of abomasal infusion of 500 mL/d (430 g of lipids/d) of water (control), TAL, or CAM administered in 10 equal doses daily. Intravenous glucose tolerance test (IVGTT) and i.v. insulin challenge (IC) were performed on d 5 after 98 and 108 h of treatment infusions, respectively. Infusion of lipids increased basal plasma NEFA concentrations on d 5 (CAM: 0.25; TAL: 0.28; control: 0.17 mmol/L). Following glucose injection, the rate of glucose clearance (CR) was lower in lipid-treated cows (CAM: 1.34; TAL: 1.48; control: 1.74%/min) and time to reach half-maximal glucose concentration (T(1/2)) was longer (CAM: 54; TAL: 47; control: 42 min). Similar responses were observed after insulin injection. Increased plasma NEFA concentration tended to decrease insulin secretion in IVGTT. Infusion of CAM increased plasma C18:3n-3 content (CAM: 26.4; TAL: 16.1; control: 20.9 g/100g of fatty acids). Data suggest that CAM had an insulin-sensitizing effect, because the disposition index and insulin sensitivity index, derived from minimal model analysis, were higher in CAM than in TAL during IVGTT, and lower insulin concentrations during IC led to similar glucose clearance in CAM as in TAL. These results indicate that elevated plasma NEFA concentration per se induces whole-body insulin resistance in late-pregnant dry cows.