Hyperlipidaemia, lack of sleep and smoking as risk factors for proteinuria among high altitude mountain trekkers

The Interactions between Smoking and Sleep

Smoking a cigarette before bed or first thing in the morning is a common habit. In this review, the relationship between smoking and sleep is investigated based on the existing literature. Out of 6504 unique items that were identified via a PubMed search related to smoking and sleep, 151 were included in this review. Tobacco smoking disrupts sleep architecture by reducing slow wave and rapid eye movement (REM) sleep and undermining sleep quality. Furthermore, smoking affects sleep-related co-morbidities, such as obstructive sleep apnea-hypopnea syndrome (OSAHS), insomnia, parasomnias, arousals, bruxism, and restless legs, as well as non-sleep-related conditions such as cardiovascular, metabolic, respiratory, neurologic, psychiatric, inflammatory, gynecologic and pediatric issues, while poor sleep quality also seems to worsen the chances of successful smoking cessation. In conclusion, the existing literature suggests that there is a wicked relation between smoking and sleep.

Hypoxia-inducible factor-1α attenuates renal podocyte injury in male rats in a simulated high-altitude environment by upregulating Krüppel-like factor 4 expression

Previous studies have shown that podocyte injury is involved in the development of proteinuria in rats under hypobaric hypoxia conditions. Prolyl hydroxylase inhibitors (PHIs) may reduce proteinuria. This study aimed to further investigate whether the protective effects of hypoxia-inducible factor 1α (HIF1α) on podocyte injury induced by hypobaric hypoxia are related to Krüppel-like factor 4 (KLF4). Rats were housed in a low-pressure oxygen chamber to simulate a high-altitude environment (5000 m), and a PHI was intraperitoneally injected. Urinary protein electrophoresis was performed and the morphology of the podocytes was observed by electron microscopy. Rat podocytes were cultured under 1% O2, and siRNA was used to interfere with KLF4 expression. The protein expression levels of HIF1α, KLF4, CD2-associated protein (CD2AP) and nephrin were determined by western blotting. Compared with those in the experimental group, the rats in the intervention group on day 14 had lower urinary protein levels, increased protein expression levels of CD2AP and nephrin, and reduced podocyte injury. The results of in vitro experiments showed that the protein expression levels of KLF4, CD2AP and nephrin were greater in the PHI intervention group and lower in the HIF1α inhibitors group than in the low-oxygen group. The protein expression of CD2AP and nephrin in the siKLF4-transfected podocytes treated with PHI and HIF1α inhibitors did not differ significantly from that in the low-oxygen group. HIF1α may be involved in reducing progressive high-altitude proteinuria by regulating KLF4 expression and contributing to the repair of podocyte injury induced by hypobaric hypoxia.

Higher peripheral neutrophil and monocyte counts are independent indicators of the presence and severity of proteinuria in apparently normal adults

BACKGROUND

Proteinuria reflects disrupted renal function in which enhanced immuno-inflammation activity plays a key role. So far, information concerning the relations between proteinuria and peripheral different leucocyte counts is limited. We thereby conducted this study aiming to obtain comprehensive information of the issue.

METHODS

Study subjects were participants of a health check programme from 2000 to 2002. Additional two enrolment criteria were (i) leucocyte analysis was checked with a same blood cell counter and (ii) urinalysis showed no pyuria or haematuria. Data of subjects were retrospectively collected and analysed by using sas program.

RESULTS

Higher neutrophil and monocyte counts, but not lymphocyte count, were significantly associated with both the presence and the severity of proteinuria (all P < 0.0001, n= 12 225). Such associations maintained significant after adjustments of age, sex, body mass index, mean blood pressure and blood levels of glycosylated hemoglobin (HbA1c), total cholesterol, triglycerides and creatinine (all P< or = 0.001, n= 12 225). There was a sharp increase in the incidence of proteinuria in association with a neutrophil count > or =4.50 x 10(9)/L (P< or = 0.0001).

CONCLUSION

Our study showed that in apparently normal adults the presence and the severity of proteinuria could be reflected by the peripheral neutrophil and monocyte counts, but not the lymphocyte count. These findings, together with the documented inflammatory basis of proteinuria and the diverse pathophysiological roles of differential leucocytes, suggest that peripheral differential leucocyte counting may be useful in predicting the course of an existing proteinuria. Perspective longitudinal follow-up studies are needed to test this presumption.

Chronic kidney disease at high altitude

With a prevalence of 10 to 11% in the general population, it is likely that many patients with chronic kidney disease will visit or reside in mountainous areas. Little is known, however, about whether short- or long-duration, high-altitude exposure poses a risk in this patient population. Given that many areas of the kidney are marginally oxygenated even at sea level and that kidney disease may result in further renal hypoxia and hypoxia-associated renal injury, there is concern that high altitude may accelerate the progression of chronic kidney disease. In this review, we address how chronic kidney disease and its management is affected at high altitude. We postulate that arterial hypoxemia at high altitude poses a risk of faster disease progression in those with preexisting kidney disease. In addition, we consider the risks of developing acute altitude illness in patients with chronic kidney disease and the appropriate use of medications for the prevention and treatment of these problems.