Chloroquine impairs maximal transdiaphragmatic pressure generation in old mice.

Aging results in increased neuromuscular transmission failure and denervation of the diaphragm muscle, as well as decreased force generation across a range of motor behaviors. Increased risk for respiratory complications in old age is a major health problem. Aging impairs autophagy, a tightly regulated multistep process responsible for clearing misfolded or aggregated proteins and damaged organelles. In motor neurons, aging-related autophagy impairment may contribute to deficits in neurotransmission, subsequent muscle atrophy, and loss of muscle force. Chloroquine is commonly used to inhibit autophagy. We hypothesized that chloroquine decreases transdiaphragmatic pressure (Pdi) in mice. Old mice (16-28 mo old; n = 26) were randomly allocated to receive intraperitoneal chloroquine (50 mg/kg) or vehicle 4 h before measuring Pdi during eupnea, hypoxia (10% O2)-hypercapnia (5% CO2) exposure, spontaneous deep breaths ("sighs"), and maximal activation elicited by bilateral phrenic nerve stimulation (Pdimax). Pdi amplitude and ventilatory parameters across experimental groups and behaviors were evaluated using a mixed linear model. There were no differences in Pdi amplitude across treatments during eupnea (∼8 cm H2O), hypoxia-hypercapnia (∼10 cm H2O), or sigh (∼36 cm H2O), consistent with prior studies documenting a lack of aging effects on ventilatory behaviors. In vehicle and chloroquine-treated mice, average Pdimax was 61 and 46 cm H2O, respectively. Chloroquine decreased Pdimax by 24% compared to vehicle (P < 0.05). There were no sex or age effects on Pdi in older mice. The observed decrease in Pdimax suggests aging-related susceptibility to impairments in autophagy, consistent with the effects of chloroquine on this important homeostatic process.NEW & NOTEWORTHY Recent findings suggest that autophagy plays a role in the development of aging-related neuromuscular dysfunction; however, the contribution of autophagy impairment to the maintenance of diaphragm force generation in old age is unknown. This study shows that in old mice, chloroquine administration decreases maximal transdiaphragmatic pressure generation. These chloroquine effects suggest a susceptibility to impairments in autophagy in old age.

Vegan, Vegetarian and Meat-Based Diets in Saudi Arabia.

Introduction One of the most essential risk factors for chronic medical conditions is dietary intake. The dietary habits in Saudi Arabia shifted towards the Western diet, which is high in fat, salt and sugar. Plant-based diets like vegetarianism and veganism have gained popularity in the last few years. Individuals commit to a plant-based diet for many reasons. Plant-based diets are associated with various health benefits but can still cause nutrition deficiencies.  Purpose The aim of the study is to examine the proportion of vegan, vegetarian and omnivore diets in Saudi Arabia. To compare between plant-eaters and meat-eaters in health, lifestyle factors and nutritional status. Methods A cross-sectional study was conducted. A previously validated online questionnaire was distributed via social media platforms. The authors used convenience sampling to collect the data. Results A total of 1018 respondents answered the survey. Most respondents 885 (87%) were omnivores, 52 were vegetarians (5%) and 81 (8%) were vegans. Moreover, 61% of the total respondents never consumed vitamin B12 supplements, and 10% consumed vitamin B12 daily. The majority of respondents 548 (54%) used no other dietary supplements, and 470 (46%) used unspecified dietary supplements. Vegan respondents were more likely than other diet categories to have healthier lifestyle features, including >3 times/week exercise (standardized residual = 3.55) and >7 hours of sleep (standardized residual = 2.44). Conclusion Majority of Saudis follow omnivore diets and the frequency of those who follow plant-based diets is very low. Those who follow a vegan diet seem to have better health rating and lifestyle compared to the omnivores. Public health officials and healthcare providers are encouraged to increase awareness among the Saudi population about the health benefits of a plant-based diet.