Browsing by Author "Domingos, F"
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- Avaliação Metabólica da LCIR na população portuguesaPublication . Serra, MA; Domingos, F
- EditorialPublication . Domingos, F
- Focus on: II – physiological principles of acid-base balance: an integrative perspectivePublication . Domingos, FNormal human metabolism leads to the daily production of large amounts of volatile and non-volatile acids. The maintenance of the pH within physiological limits is a demanding task in which several mechanisms are involved. The most immediate answer comes from several physiological buffers that quickly neutralize pH deviations caused by the addition of strong acids or bases to the body. Bicarbonate/carbonic acid is the most important buffer pair of the extracellular milieu, but is chemically inefficient and depends on the continuous activity of the lung and kidney. Other physiological buffers have higher efficacy and are very important in the intracellular environment and renal tubules. The capacity of the various chemical buffers is kept by operating in an open system and by several controlling mechanisms. The lung is responsible for the elimination of the carbon dioxide (CO2) produced in the body. In metabolic disorders, respiratory adjustment of the elimination of CO2 prolongs the effect of the bicarbonate/carbonic acid buffer, but this process consumes bicarbonate. The kidney contributes to acid-base balance through several mechanisms: 1) controls the reabsorption of filtered bicarbonate; 2) regenerates bicarbonate consumed in buffer reactions; 3) eliminates non-volatile acids. Renal elimination of acid and bicarbonate regeneration is only possible due to the existence of several urinary buffers and to the ability of the kidneys to produce ammonia
- Metabolic syndrome: a multifaceted risk factor for kidney stonesPublication . Domingos, F; Serra, AKidney stones and metabolic syndrome (MetS) are common conditions in industrialized countries. There is growing evidence of associations between kidney stone disease and MetS or some of its components. The link between uric acid stones and MetS is well understood, but the link with calcium oxalate (CaOx) stones, the most common kidney stone composition, is more complex, and MetS is frequently overlooked as a risk factor for calcium nephrolithiasis. The physiopathological mechanisms of kidney stone disease in MetS are reviewed in this article. Uric acid stones are a consequence of the excessively acidic urine that results from insulin resistance. The pathophysiology of CaOx stones may include: increased excretion of lithogenesis promoters and decreased excretion of inhibitors; increased risk of Randall's plaque development; and inflammatory damage to renal epithelia by oxidative stress, as a consequence of the insulin-resistant milieu that characterizes MetS. The last mechanism contributes to the adhesion of CaOx crystals to subepithelial calcium deposits working as anchor sites where stones can grow. The predominant MetS features could determine the chemical composition of the stones in each patient. Kidney stones may be a renal manifestation of MetS and features of this syndrome should be looked for in patients with idiopathic nephrolithiasis.
- Modelos Teóricos da Ética MédicaPublication . Domingos, F
- Nephrolithiasis is associated with an increased prevalence of cardiovascular diseasePublication . Domingos, F; Serra, MABackground: Nephrolithiasis has been associated with hypertension, obesity and diabetes Mellitus. The prevalence of adverse cardiovascular outcomes among kidney stone formers (KSF) is unknown. Methods: We examined the IV Portuguese National Health Survey for documenting possible associations between nephrolithiasis, cardiovascular diseases, diabetes and obesity in the Portuguese adult population. Results: We obtained 23,349 questionnaires from individuals with ≥ 15 year-old. The prevalence of kidney stone disease was 7.3%. The prevalence of hypertension was higher among KSF when compared with the general population (50.4% vs. 30.2%; p < 0,001). Age and obesity significantly increase the risk for nephrolithiasis. After adjusting for age and body mass index, KSF have higher prevalence of hypertension (odds-ratio: 1.841; 95% CI: 1.651 – 2.053), diabetes Mellitus (odds-ratio: 1.475; 95% CI: 1.283 – 1.696; p < 0.001), myocardial infarction (odds-ratio: 1.338; 95% CI: 1.003 – 1.786; p < 0.05), and stroke (odds-ratio: 1.330; 95% CI: 1.015 – 1.743; p < 0.05) as compared with non-stone formers. Conclusions: Kidney stone disease is associated with a higher prevalence of chronic diseases and adverse cardiovascular outcomes when compared with the general population.
- Water-electolyte balance and acid-base equilibrium: a perspective on homeostatic physiologyPublication . Correia, P; Domingos, F