Sex-related differences in endothelial function and blood viscosity in the elderly population

Risk factors for unplanned weaning of continuous renal replacement therapy in ICU patients: a meta-analysis

OBJECTIVE

To systematically review the risk factors for unplanned weaning during continuous renal replacement therapy in ICU patients.

METHODS

A combination of subject words + free words was used to search the relevant literature published in CNKI, Wanfang, VIP, CBM, PubMed, EMbase, Web of Science, Cochrane Library, Mediline and other databases. The search period was from the establishment of the databases to June 25, 2024. Revman 5.4 software and Stata15.0 software was used to meta-analyze the risk factors for unplanned weaning during continuous renal replacement therapy in ICU patients.

RESULTS

A total of 23 studies were included in this meta-analysis, describing 15 variables, 3793 patients, and using 7197 filters. Meta-analysis results showed that risk factors for unplanned weaning during continuous renal replacement therapy in ICU patients were as follows: Low mean arterial pressure [OR = 1.02, 95%CI (1.00, 1.03), p < 0.05], hypothermia [OR = 3.40, 95%CI (1.78, 6.47), p < 0.05], age (≥60 years) [OR = 4.45, 95%CI (3.18, 6.22), p < 0.05], comorbid underlying disease [OR = 3.63, 95%CI (2.70, 4.88), p < 0.05], agitation [OR = 4.97, 95%CI (3.20, 7.74), p < 0.05], no anticoagulant use [OR = 1.65, 95%CI (1.25, 2.17), p < 0.05], short activated partial prothrombin time [OR = 1.23, 95%CI (1.13, 1.34), p < 0.05], hyper-hematocrit [OR = 1.73, 95%CI (1.13, 2.66), p = 0.01], low ionized calcium concentration [OR = 1.48, 95% CI (1.08, 2.02), p = 0.01], CRRT that was treated at a high dose [OR = 1.42, 95%CI (1.14, 1.76), p < 0.05], mechanical ventilation [OR = 4.25, 95%CI (2.67, 6.77), p < 0.05], and lack of dedicated care [OR = 5.08, 95%CI (2.51, 10.28), p < 0.05]. However, it is unclear whether platelet count, prothrombin activity, and blood flow velocity are risk factors for unplanned weaning during CRRT in ICU patients, and more studies are needed for further validation.

CONCLUSION

Available evidence suggests that a variety of factors contribute to unplanned weaning of CRRT in ICU patients. Early detection of these risk factors is essential for healthcare professionals to develop preventive and curative strategies.

REGISTRATION

This study is registered on the PROSERO website under registration number CRD42024543554.

Sex differences in the predictors of skeletal muscle microvascular reactivity in older individuals

Aging is associated with an increased risk of cardiovascular disease and vascular dysfunction. Reduced nitric oxide bioavailability is considered one of the key mechanisms underlying vascular dysfunction in large arteries of older adults. However, the relationship between cardiovascular disease risk factors, nitric oxide bioavailability, and skeletal muscle microvascular reactivity, an early hallmark in cardiovascular disease progression, is unclear in older individuals. Also uncertain is whether this relationship is influenced by sex. Therefore, this study assessed the association between cardiovascular disease risk factors, circulating markers of nitric oxide availability (plasma nitrate and nitrite), and skeletal muscle microvascular reactivity in older individuals. First, we confirmed in a cohort of young and older individuals that aging is associated with skeletal muscle microvascular dysfunction. Next, we observed that skeletal muscle microvascular reactivity (P = 0.653; η2 = 0.016) and circulating nitric oxide metabolites (Nitrate: P = 0.641, η2 = 0.011; Nitrite: P = 0.560, η2 = 0.017; NOx: P = 0.639, η2 = 0.011) did not differ between older males and females. Finally, using multivariate regression models, we found that: (i) the number of cardiovascular risk factors was negatively associated with skeletal muscle microvascular reactivity in older males and females (B = -0.132, P = 0.044); (ii) the relationship between plasma nitrite and skeletal muscle microvascular reactivity was influenced by sex (F = 6.837, P = 0.016); and (iii) skeletal muscle microvascular reactivity in older females displayed a strong positive association with plasma nitrite (R2 = 0.720, P < 0.001). While the impact of cardiovascular disease risk factors on skeletal muscle microvascular reactivity was not influenced by sex, sex-related discrepancies were found in the relationship between nitric oxide bioavailability and skeletal muscle microvascular reactivity in older individuals.

Epidemiology of Canine Wei Syndrome and Its Hemorheology Characteristics

Canine paraplegia is a common condition in small animal medicine, referred to as Wei Syndrome (WS) in Traditional Chinese Veterinary Medicine (TCVM). Common clinical manifestations encompass hind limb paralysis, motor dysfunction, muscle atrophy, and the absence of pain perception. WS is considered a difficult-to-treat disease in small animal practice. The objective of this study was to investigate the epidemiology of canine WS and the characteristics of hemorheology. A total of 53 dogs with WS and 53 healthy dogs were included in this study. A retrospective case-controlled study design was employed. Data regarding the gender, season of WS occurrence, breed, and age of dogs with WS, as well as hemorheology from dogs with WS and healthy dogs, were collected and analyzed using SPSS 27.0. The study findings revealed that male dogs were more susceptible to WS (77.36%, 41/53). WS cases occurred more frequently in Winter (33.96%, 18/53), and were commonly found in Poodle breeds (43.40%, 23/53). The most affected age of WS was between 3 and 6 years old (54.72%, 29/53). Except for plasma viscosity and fibrinogen, the hemorheology indices of canine WS were significantly higher than those of healthy dogs (p < 0.05), especially in male dogs, Poodles and Bulldogs, those between 3 to 10 years, and in Autumn and Winter. This study provides evidence that male Poodles and Bulldogs aged 3 to 6 years are more prone to developing WS, with Winter being the season of high disease incidence. Abnormal hemorheology is a characteristic feature in dogs with WS, which should be considered during the treatment of WS.

Age and sex differences in microvascular responses during reactive hyperaemia

Microvascular impairments are typical of several cardiovascular diseases. Near-infrared spectroscopy (NIRS) combined with a vascular occlusion test provides non-invasive insights into microvascular responses by monitoring skeletal muscle oxygenation changes during reactive hyperaemia. Despite increasing interest in the effects of sex and ageing on microvascular responses, evidence remains inconsistent. Therefore, the present study aimed to investigate the effects of sex and age on microvascular responsiveness. Twenty-seven participants (seven young men and seven young women; seven older men and six older women; aged 26 ± 1, 26 ± 4, 67 ± 3 and 69 ± 4 years, respectively) completed a vascular occlusion test consisting of 5 min of arterial occlusion followed by 5 min reperfusion. Oxygenation changes in the vastus lateralis were monitored by near-infrared spectroscopy. The findings revealed that both women (referring to young and older women) and older participants (referring to both men and women) exhibited lower microvascular responsiveness. Notably, both women and older participants demonstrated reduced desaturation (-38% and -59%, respectively) and reperfusion rates (-24% and -40%, respectively) along with a narrower range of tissue oxygenation (-39% and -39%, respectively) and higher minimal tissue oxygenation levels (+34% and +21%, respectively). Women additionally displayed higher values in resting (+12%) and time-to-peak (+15%) tissue oxygenation levels. In conclusion, this study confirmed decreased microvascular responses in women and older individuals. These results emphasize the importance of considering sex and age when studying microvascular responses. Further research is needed to uncover the underlying mechanisms and clinical relevance of these findings, enabling the development of tailored strategies for preserving vascular health in diverse populations.