Long-term reproducibility of routine ambulatory blood pressure monitoring in stable pediatric renal transplant recipients

BACKGROUND: The aim of this study was to evaluate, in stable pediatric renal transplant recipients, the long-term reproducibility of average office and ambulatory blood pressure (BP) readings and day-to-night BP variability under similar clinical conditions. METHODS: The study involved 18 pediatric kidney transplant recipients who had repeated routine office and 24-h ambulatory BP monitoring (ABPM) in three visits, 12 months apart, over a 2-year period. Reproducibility of office and ambulatory BP averages between pairwise measurements were analyzed by calculating the mean difference and the standard deviation of the difference (SDD). Nondippers were arbitrarily defined by applying both a pediatric and an adult definition, respectively. RESULTS: Throughout the 2-year period, there were no significant differences in mean office, 24-h, daytime, night-time systolic, and diastolic BP values. Overall, SDD were lower for ambulatory BP recordings than for office BP measurements indicating a better long-term reproducibility for ABPM compared with office BP readings. The SDD for systolic and diastolic BP ranged from 12.4 to 13.7 and 6.3 to 9.5 for office BP and from 6.2 to 7.3 and 5.1 to 5.6 for 24-h BP, respectively. Regardless of the definition applied to define dipper and nondipper status, only half of the study group showed consistency in their circadian BP variability when comparing the three ABPMs. CONCLUSIONS: The present study demonstrates that long-term reproducibility of ABPM is superior to that for office measurements. Day-to-night BP variability, however, appears to change over time, making it questionable to classify a recipient as a dipper or nondipper during a single ABPM recording.     

Circulating leptin and thyroid dysfunction

The identification and sequencing of the ob gene and its product, leptin, in 1994 opened new insights in the study of the mechanisms controlling body weight and led to a surge of research activity. Since its discovery, leptin has been the subject of an enormous amount of work especially within the fields of nutrition, metabolism and endocrinology. Leptin is accepted as an adipose signal, and even though the underlying mechanisms are not fully clarified, leptin, in addition to the thyroid hormones, is believed to be involved in regulation during the switch from the fed to the starved state. It is not clear whether leptin and the melanocortin pathways interact with the thyroid axis under physiological conditions other than during starvation or in response to severe illness, both states in which the hypothalamo-pituitary-thyroid axis may be severely suppressed. In addition to the suggested central relationship between leptin and thyroid hormones, there might also be a peripheral relationship although this effect is not clear. Both thyroid hormones and leptin might be involved in the adaptive thermogenesis through mitochondrial uncoupling proteins and heat production because both thyroxine and triiodothyronine are involved in the starvation-induced decrease in thermogenesis. Both rodent and human studies of leptin have failed to show any consistent relationship between thyroid function and serum leptin concentrations. However, leptin might have an important role in thyroid pathophysiology due to thyroid hormone involvement in thermogenesis and regulation of uncoupling proteins. In this review, we have focused on leptin in relation to thyroid pathophysiology.     

Improved Hand Function,Self‐Rated Health,and Decreased Activity Limitations: Results After a Two‐Month Hand Osteoarthritis Group Intervention

Objective

To evaluate the effects on hand function, activity limitations, and self‐rated health of a primary care hand osteoarthritis (OA) group intervention. Hand OA causes pain, impaired mobility, and reduced grip force, which cause activity limitations. OA group interventions in primary care settings are sparsely reported.

Methods

Sixty‐four individuals with hand OA agreed to participate; 15 were excluded due to not fulfilling the inclusion criteria. The 49 remaining (90% female) participated in an OA group intervention at a primary care unit with education, paraffin wax bath, and hand exercise over a 6‐week period. Data were collected at baseline, end of intervention, and after 1 year. Instruments used were the Grip Ability Test (GAT), the Signals of Functional Impairment (SOFI), dynamometry (grip force), hand pain at rest using a visual analog scale (VAS), the Patient‐Specific Functional Scale (PSFS), the Quick Disabilities of the Arm, Shoulder, and Hand (Quick‐DASH), and the EuroQol VAS (EQ VAS). Data were analyzed using nonparametric statistics.

Results

Hand function, activity limitation, and self‐rated health significantly improved from baseline to end of intervention, grip force (right hand: P < 0.001; left hand: P = 0.008), SOFI (P = 0.011), GAT (P < 0.001), hand pain at rest (P < 0.001), PSFS (1: P = 0.008, 2: P < 0.001, and 3: P = 0.004), Quick‐DASH (P = 0.001), and EQ VAS (P = 0.039), and the effects were sustained after 1 year.

Conclusion

The hand OA group intervention in primary care improves hand function, activity limitation, and self‐rated health. The benefits are sustained 1 year after completion of the intervention.

     

Prospective study of left ventricular function after radiofrequency ablation of atrioventricular junction in patients with atrial fibrillation.

BACKGROUND--In patients with drug resistant incessant supraventricular tachycardia, radiofrequency induced ablation of the atrioventricular junction and pacemaker implantation have hitherto been considered a treatment of last resort. OBJECTIVE--To assess the short and long term effects of ablation of the atrioventricular junction on systolic and diastolic left ventricular function in patients with atrial fibrillation with and without impaired left ventricular function. PATIENTS--29 patients (19 men; mean age 65 (SD 7) years (range 50-76)) undergoing ablation of the atrioventricular junction for drug refractory atrial fibrillation were examined a mean of 2, 65, and 216 days after ablation of the bundle of His. MAIN OUTCOME MEASURES--Left ventricular ejection fraction and early filling deceleration times (Edec) were assessed by Doppler echocardiography after 1 to 2 hours of ventricular pacing at a rate of 80 beats/minute. RESULTS--In 14 patients with a left ventricular ejection fraction < 50% left ventricular ejection fraction increased significantly from 32% (11%) to 39% (11%) (65 days) and 45% (11%) (216 days) (P < 0.001); Edec increased from 142 (46) ms to 169 (57) ms (65 days) and 167 (56) ms (216 days) (P < 0.05). In 15 patients with an ejection fraction > or = 50% at the initial examination no significant change in systolic function was observed. CONCLUSIONS--In patients with left ventricular dysfunction long term improvement of systolic and diastolic left ventricular function was seen after ablation of the atrioventricular junction for rate control of atrial fibrillation. This procedure had no adverse effects on normal left ventricular function.     

Sinus node dysfunction during long-term lithium treatment.

BACKGROUND AND OBJECTIVE--Lithium has occasionally been reported to cause symptomatic sinus node bradyarrhythmias. The prevalence and mechanism of these arrhythmias during long-term treatment are unknown. The aims of this study were (a) to evaluate the systemic effects of lithium treatment on cardiac conduction in individuals who were free from cardiovascular disorders; (b) to assess the prevalence of lithium treatment in a group of patients with pacemakers; and (c) to evaluate the interaction between the parasympathetic limb of the autonomous nervous system and the sinus node cells during long-term lithium treatment. PATIENTS AND METHODS--45 patients who had been treated with lithium for > 12 months were investigated in a long-term electrocardiography study. Only patients without cardiovascular disease, or concomitant chronotropic medication, or metabolic disorders known to cause rhythm disturbances were included. An age-stratified population was used as a reference group. 21 patients also underwent analysis of carotid sinus pressure and sinus cycle length before and after atropine to clarify whether neural mechanisms were involved. The prevalence of lithium treated patients was determined in 650 patients with pacemakers. RESULTS--(a) Signs of moderate sinus node dysfunction (sinus arrest > 1.5 s, minimum heart rate < 50 beats/min) were found in 56% and 78% respectively in the lithium-treated group compared with 30% and 30% respectively in the reference group (p < 0.01). Severe sinus node dysfunction was equally common in both groups. (b) The prevalence of chronic lithium treatment in the pacemaker population was 0.46%. (c) Sinus cycle variations were abnormal in the basal state in three (14%) patients and in 11 (52%) patients after atropine despite signs of intact and normal parasympathetic innervation. CONCLUSIONS--Depressed sinus node function was significantly more common in a lithium-treated population than in an age-stratified reference group. Clinically significant dysfunction, however, was uncommon. The effect of lithium on the sinus node seemed to be intrinsic and was not caused by increased parasympathetic tone.     

Intravenous Immunoglobulin and Rituximab for Cerebellar Ataxia with Glutamic Acid Decarboxylase Autoantibodies

Cerebellar ataxia associated with glutamic acid decarboxylase autoantibodies (GAD-ab) is a rare and usually slow progressive disease with moderate to severe gait and limb ataxia, dysarthria, and nystagmus. The treatment for this condition is still being discussed. We report the cases of three patients with GAD-ab cerebellar ataxia treated successively with intravenous immunoglobulin (IVIg) and rituximab. Symptoms improved in one case after rituximab therapy and were stabilized in another after a combined therapy of IVIg and rituximab. The third patient continued to worsen despite these treatments. We conclude that IVIg and rituximab therapy could improve or stabilize GAD-ab cerebellar ataxia. Early treatment, the lack of cerebellar atrophy on magnetic resonance imaging, and a subacute onset of the symptoms could be decisive prognostic factors.     

Hemodynamic causes of exercise intolerance in Fontan patients

Background

Exercise intolerance is frequent among Fontan patients and an important determinant for quality of life. This study investigated the hemodynamic causes of impaired exercise capacity in Fontan patients with particular focus on the influence of stroke volume index (SVI) and heart rate (HR).

Methods and results

In 38 Fontan patients, peak oxygen consumption (VO₂), SVI and HR were recorded during incremental load exercise test and compared with 19 age and gender matched controls.SVI (ml/m²) was lower in patients than controls during warm-up (28[26–31] vs. 35[30–39], p = 0.0093), at submaximal (40[37–43] vs. 55[51–59], p < 0.0001) and at maximal exercise (38[35–40] vs. 54[51–58], p < 0.0001). Similarly, HR (% of expected maximum) was lower in patients at warm-up (45[43–48]% vs. 64[57–64]%, p < 0.0001), submaximal (71[68–75]% vs 85[82–88]%, p < 0.0001) and maximal exercise (84[80–88]% vs. 97[95–99]%, p < 0.0001). Furthermore, SVI dropped 14% (from 44[41–48] to 38[35–40] ml/m²) in Fontan patients from the peak plateau to maximal exercise vs. 5% (from 57[53–61] to 54[51–58] ml/m²) in controls, p < 0.0001. The low SVI and HR explained 67% and 20% of the difference in peak VO₂ between Fontan patients and controls respectively.

Conclusion

SVI decreased significantly in Fontan patients near the end of maximal effort exercise. The low SVI at maximal exercise was the most important hemodynamic factor limiting exercise capacity in Fontan patients, whereas chronotropic impairment had a smaller impact. The low SVI and HR at maximal exercise accounted for the difference in peak VO₂ between Fontan patients and controls in this study.

Clinical trial registration

http://www.cvk.sum.dk/CVK/Home/English.aspx (protocol nr: H-3-2010-045).     

The degree of fetal metformin exposure does not influence fetal outcome in gestational diabetes mellitus

The purpose of the study was to examine in vivo placental transfer of metformin, its association with neonatal outcome in metformin-treated gestational diabetes (GDM) patients, and influence of metformin exposure on maternal glycemic control and weight gain. Two hundred and seventeen GDM patients were randomized to metformin or insulin in Turku University Hospital, Finland. Metformin concentrations were determined by mass spectrometry in maternal serum at 36 gestational weeks (gw) and at birth, and in umbilical cord blood. Main outcome measures were birth weight, gw at birth, umbilical artery pH and neonatal hypoglycemia, maternal weight gain, HbA1c and fructosamine concentration. Median umbilical cord/maternal serum metformin concentration ratio was 0.73. There were no differences in birth weight measured in grams or SD units (p = 0.49), or gw at birth (p always ≥0.49) between insulin- and metformin-treated patients stratified by trough metformin concentration tertiles measured at 36 gw. Rate of neonatal hypoglycemia (p = 0.92) and umbilical artery pH value (p = 0.78) was similar in insulin- and metformin-treated patients stratified by cord metformin concentration tertiles. Maternal glycemic control was similar in metformin concentration tertiles at 36 gw. Maternal weight gain was 223 g greater per week (p = 0.038) in the lowest metformin tertile compared to other tertiles combined. Maternal and fetal exposure to metformin is similar. Maternal or fetal metformin concentrations do not predict maternal glycemic control or neonatal outcome, but low maternal exposure may lead to greater maternal weight gain.