Renal hemodynamic and tubular responses to salt in women using oral contraceptives

BACKGROUND: The use of oral contraceptives is associated with an increased risk of developing hypertension but the mechanisms of this hypertensive effect are not completely defined. The purpose of the present study was to assess prospectively the systemic and renal hemodynamic and tubular responses to salt in women taking oral contraceptives. METHODS: Twenty seven young healthy normotensive women taking oral contraceptives containing monophasic combination of 30 microg ethynilestradiol and 150 microg desogestrel for>6 months were enrolled. All women were assigned at random to receive a low (40 mmol/day) or a high (250 mmol/day) sodium diet for 1 week on two consecutive menstrual cycles during the active oral contraceptive phase. At the end of each diet period, 24-hour ambulatory blood pressure, renal hemodynamics, sodium handling, and hormonal profile were measured. RESULTS: The blood pressure response to salt on oral contraceptives was characterized by a salt-resistant pattern with a normal circadian rhythm. Salt loading results in an increase in glomerular filtration rate (GFR) (P < 0.05 vs. low salt), with no change in the renal plasma flow, thus leading to an increase in the filtration fraction (P < 0.05). At the tubular level, women on oral contraceptives responded to a low salt intake with a marked increased in proximal sodium conservation (P < 0.01 vs. high salt) and with an almost complete reabsorption of sodium reaching the distal tubule. After sodium loading, both the proximal and the distal reabsorption of sodium decreased significantly (P < 0.01). CONCLUSION: The use of oral contraceptives is not associated with an increased blood pressure response to salt in young normotensive women. However, oral contraceptives affect the renal hemodynamic response to salt, a high salt intake leading to an increase in GFR and filtration fraction. This effect is possibly mediated by the estrogen-induced activation of the renin-angiotensin system. Oral contraceptives also appear to increase the tubular responsiveness to changes in sodium intake. Taken together, these data point out evidence that synthetic sex steroids have a significant impact on renal function in women. The renal effects of oral contraceptives should be taken into account when managing young women with renal diseases.     

Do depressive episodes lead to accumulation of vulnerability in the elderly?

The vulnerability-accumulation (or scarring) hypothesis postulates that the experience of depression induces a lasting increase in vulnerability, and through this raises the risk of recurrence. We examined the validity of the vulnerability-accumulation model for depressive episodes in later life. The sample comprised 26 elderly persons who had remitted from a depressive episode and 96 control respondents who were all selected from the participants of a large community survey among persons aged 57 years or more. Several psychosocial vulnerability indicators were assessed premorbidly, during the depressive episode and after remission. High levels of psychological distress, low life satisfaction, chronic somatic diseases, high neuroticism, and low scores on extraversion, mastery, and self-efficacy appeared to be predictors of depression in this sample. During the depressive episode, psychological distress was higher and life satisfaction, physical, role, and social functioning, as well as feelings of self-efficacy lower than before the episode. Physical and role functioning, cognitive function, and self-efficacy were lower after remission compared to premorbid levels, but (other) personality indices had not changed after remission compared to premorbid levels. Furthermore, we failed to find differences between first and recurrent episodes. Support for the vulnerability-accumulation model was limited at the most. Although psychosocial scarring may occur in the elderly, our findings tentatively suggest that this accumulation does not manifest itself in major vulnerability indicators such as neuroticism.     

Who are patients on conventional antipsychotics?

The advent of atypical antipsychotics presented psychiatrists with an effective way of treating psychosis without the many side effects associated with conventional agents. Given the superiority of atypical antipsychotics, we examined demographic information and treatment histories of patients currently treated with conventional antipsychotics, especially in regard to treatment with atypical agents. Medication histories and demographic information for 276 patients admitted to an urban hospital were obtained by patient/family interviews and review of medical records. Chi-square and logistic regression tests were used to analyze data for possible predictive factors of which patients within the sample were still receiving conventional antipsychotics for treatment. Seventy-eight (28%) patients were currently being treated with conventional antipsychotics. More than half of them had never received a trial of an atypical agent. African-Americans, who are more likely to suffer adverse effects from conventional antipsychotics, and substance abusers were overrepresented in this group. It is unclear to what extent ethnic or cultural bias played a role in determining medication choice. Because conventional antipsychotics are associated with more side effects and greater medication nonadherence, these patients should be evaluated for appropriateness of a trial with an atypical agent even if they are currently stable with a conventional antipsychotic.     

Communication and the hearing-impaired patient

Hearing impairment affects significant numbers of the people who are most likely to use healthcare services. Nursing skills in this area still fall short of acceptable standards. Awareness of the scale of the problem, identification of those affected and knowledge of how best to communicate with them are crucial to providing sensitive and individualized care.     

Relationship of femoral artery ultrasound measures of atherosclerosis with chronic kidney disease

Background

Chronic kidney disease (CKD) is strongly associated with peripheral artery disease (PAD). Detection of subclinical PAD may allow early interventions for or prevention of PAD in persons with CKD. Whether the presence of atherosclerotic plaque and femoral intima-media thickness (IMT) are associated with kidney function is unknown.

Relation of circulating oxidized LDL to obesity and insulin resistance in children

Kelly AS, Jacobs DR Jr, Sinaiko AR, Moran A, Steffen LM, Steinberger J. Relation of circulating oxidized LDL to obesity and insulin resistance in children. Introduction: Circulating oxidized low‐density lipoprotein (LDL), a marker of oxidative stress, is associated with obesity, insulin resistance, metabolic syndrome, and cardiovascular disease in adults. However, little is known about its relation to insulin resistance and cardiovascular risk factors in children. The purpose of this study was to assess the relation of oxidative stress, measured by circulating oxidized LDL, with measures of adiposity and insulin resistance in children. Methods: Oxidized LDL, measures of body fatness (body mass index: BMI, percent body fat, waist circumference, percent trunk fat, abdominal visceral and subcutaneous fat), insulin resistance with euglycemic insulin clamp (Mlbm), blood pressure, and blood lipids were obtained in 78 children. Oxidized LDL was compared between normal weight children (BMI < 85th percentile) and overweight/obese children (BMI ≥ 85th percentile) and levels were evaluated for associations with body fatness and insulin resistance. Results: Oxidized LDL levels were significantly higher in overweight/obese vs. normal weight children (p < 0.0001). Oxidized LDL was significantly correlated with BMI, percent body fat, waist circumference, percent trunk fat, abdominal visceral fat, and abdominal subcutaneous fat (all p‐values <0.0001). Moreover, oxidized LDL was negatively correlated with Mlbm, even after adjustment for adiposity (p < 0.01). Conclusions: Oxidized LDL is significantly associated with adiposity and with insulin resistance, independent of body fatness, in children. Oxidative stress may be independently related to the development of insulin resistance early in life, especially in obese youth.