Heart rate variability and heart rate recovery in patients with type 1 diabetes mellitus.

OBJECTIVE: Patients with diabetes mellitus (DM) are at an increased risk of sudden cardiac death (SCD) partly explained by cardiac autonomic neuropathy (CAN). There have been fewer studies to evaluate CAN using heart rate variability (HRV) and heart rate recovery (HRR) in patients with type 2 DM.To our knowledge, there has been no study to investigate the association between HRR, HRV and type 1 DM. The purpose of this study was to examine the changes in HRR and HRV measurements in type 1 diabetic patients. METHODS: The study population consisted of 35 consecutive patients with type 1 diabetes and 35 sex- and age-matched non-diabetic controls. We performed electrocardiography, echocardiography, Holter analysis, exercise stress test, routine biochemical tests including haemoglobin Ale, high-sensitivity C-reactive protein and evaluated the clinical characteristics. HRR was calculated by subtracting the heart rate values at the first minute of the recovery phase from the peak heart rate. Abnormal HRR was defined as HRR < or = 18 beats.The HRV analysis was performed in both time domain and frequency domain. RESULTS: In HRV analysis, type 1 diabetic patients had significantly lower time domain [SDNN (P=0.041), SDANN (P=0.016), r-MSSD (P<0.001), pNN50 (P<0.001)] and frequency domain [total power (P=0.002), VLF (P<0.001), LF (P<0.001), HF (P=0.001), LF/HF (P=0.034)] HRV parameters as compared to controls. In logistic regression analysis, the HRR (OR 0.927, 95% CI 0.872 to 0.985, P= 0.014), METs (OR 0.562, 95% CI 0.355 to 0.890, P= 0.014), pNN50 (OR 0.729, 95% CI 0.566 to 0.941, P= 0.015) and HF (OR 0.952, 95% CI 0.911 to 0.994, P= 0.027) were independently associated with type 1 DM. CONCLUSION: The results of this study showed that HRV parameters and HRR were significantly reduced in patients with type 1 versus healthy controls. We found that HRV parameters correlated with HRR in type 1 diabetic patients. There is a relationship between CAN and inflammation and also, there may be a relationship between CAN and intensive glycaemic control according to this study.

Alterations of plasma magnesium, copper, zinc, iron and selenium concentrations and some related erythrocyte antioxidant enzyme activities in patients with Alzheimer's disease.

The aim of the present study is to evaluate the status of plasma essential trace elements magnesium (Mg), copper (Cu), zinc (Zn), iron (Fe) and selenium (Se) concentrations and their some related antioxidant enzyme activities, erythrocyte glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) activities in patients with Alzheimer's disease (AD). Fifty patients with AD and fifty healthy control subjects were included in this study. Plasma Cu and Zn concentrations by atomic absorption spectrometry (AAS), plasma Mg and Fe concentrations by spectrophotometric methods and plasma Se concentrations by graphite furnace AAS were determined. Erythrocyte GPx, SOD and CAT activities were measured by spectrophotometric methods. Plasma Mg, Cu, Zn, Fe and Se levels and erythrocyte GPx, SOD and CAT activities were found to be significantly lower in patients with AD compared with controls. These results suggest that alterations in essential trace elements and their related enzymes may play a role in the etiopathogenesis of AD. Also, there is a defect in the antioxidant defense system, which may lead to oxidative damage in patients with AD. The changes in antioxidant enzyme activities may be secondary to the alterations in their cofactor concentrations.

A chromosomal-effect study of intensive phototherapy versus conventional phototherapy in newborns with jaundice.

In this study, we aimed to make a comparison between chromosomal effects caused by conventional phototherapy and intensive phototherapy in jaundiced newborns. The study group included 83 newborns with gestation age of > or =35 weeks, and on days 3-10 after birth. Newborns were divided into four groups on the basis of total serum bilirubin (TSB) levels upon admission and need for phototherapy. The intensive group (n=19) consisted of newborns who received light-emitting diode (LED) phototherapy, the conventional group (n=23) consisted of newborns who received conventional phototherapy, the jaundiced control group (n=21) consisted of newborns whose TSB levels were higher than 10mg/dL (average = 13.7 + /-1.5 mg/dL) on admission and who did not receive phototherapy, and the non-jaundiced control group (n=20) consisted of newborns whose TSB levels were less than 5 mg/dl (average = 3.6 +/- 0.8 mg/dL). TSB level of the intensive group at admission was 20.2 +/- 1.3 mg/dL, whereas the level of conventional group was 19.6 +/- 1.5 mg/dL. Blood samples were taken from all infants on admission to determine sister chromatid exchange (SCE1) frequency. Blood sampling was repeated on discharge (SCE2) of infants who had received phototherapy. Demographic information, hospitalization details and the rate of decline in TSB were recorded, and frequencies of SCE1 and SCE2 were compared. There was no difference in demographic information among the four groups. SCE1 frequencies in 50 metaphases were evaluated in the intensive, conventional, jaundiced control and non-jaundiced control groups, and the SCE1 frequency was determined as 9.37/cell, 9.54/cell, 9.23/cell and 6.17/cell, respectively. The SCE1 frequency of the jaundiced groups (intensive, conventional and newborns-with-jaundice control group) was significantly higher than that in the non-jaundiced control group (p = 0.001). There was no significant difference between the intensive group and the conventional group in SCE2 frequency (13.5/cell vs. 13.55/cell, p = 0.39). SCE2 frequency was higher than SCE1 frequency in both the intensive and conventional groups (p = 0.001). A strong correlation was found between admission TSB and SCE1 frequency (p = 0.001; r = 0.79). The rate of decline in TSB was higher in the intensive group compared with the conventional group (0.26mg/(dLh) vs. 0.14 mg/(dLh); p = 0.001). We found that intensive and conventional phototherapies similarly increase SCE frequency in newborns. There was a strong, positive correlation between the TSB-on-admission level and SCE1 frequency. In the light of this study, we may conclude that intensive and conventional phototherapies may have an effect on chromosomes in jaundiced newborns. TSB levels higher than 10mg/dL are, too, reported hazardous on chromosomes. Further studies are warranted to elucidate this relationship.

Ceruloplasmin, copper, selenium, iron, zinc, and manganese levels in normal and sulfite oxidase deficient rat plasma: effects of sulfite exposure.

A noticeable effect of sulfite treatment was observed on the plasma ceruloplasmin ferroxidase activity of rats with normal sulfite oxidase activity when compared to normal controls. The plasma levels of selenium, iron, and zinc were unaffected by sulfite in normal and sulfite oxidase (SOX)-deficient rats. While plasma level of Mn was decreasing, plasma Cu level increased in SOX-deficient rats. Treating SOX-deficient groups with sulfite did not alter plasma level of Mn but made plasma level of Cu back to its normal level. This is the first evidence that Cu and Mn status were affected in experimental sulfite oxidase deficiency induced by low molybdenum diet with tungsten addition deserving further research to determine the underlying mechanisms of these observations in experimental sulfite oxidase deficiency.