Elevated micronuclei frequency in type 2 diabetes with high glycosylated hemoglobin.

AIM: The role of oxidative damage to DNA due to hyperglycemia is well known. In the current study we have evaluated the induction of micronuclei due to increased glycosylation in type 2 diabetes. METHODS: Forty-nine subjects divided into two groups of normoglycemic controls and type 2 diabetic cases were recruited in the study. Whole blood was cultured and micronuclei were scored in all the cases. This was correlated with age, sex, blood glucose levels and glycosylated hemoglobin. RESULTS: Age and sex matched diabetic patients had an increased micronuclei frequency in response to elevated glycosylation of hemoglobin (R(2)=0.229, p=0.037) compared to normoglycemic subjects. CONCLUSION: The increased glycosylation seems to induce oxidative damage in the DNA of the diabetic patients, which manifests as an increased micronuclei frequency. This has a potential to be used as a biomarker for subsequent diabetic complications.

Association of common chronic infections with coronary artery disease in patients without any conventional risk factors.

BACKGROUND & OBJECTIVES: Report from the west suggest an association of infections and inflammation with atherosclerotic coronary artery disease (CAD). Entire microbial burden from several simultaneous chronic infections could be more important than a single infection in promoting atherosclerosis. No study has been done in Indian population, investigating the association of various chronic infections with CAD. We therefore evaluated the presence of markers of chronic infections in CAD patients having no conventional risk factors and healthy individuals in a tertiary care hospital in north India. METHODS: Seropositivity to IgG antibodies was investigated for Chlamydia pneumoniae, Mycoplasma pneumoniae, and Helicobacter pylori in 30 CAD patients with no conventional risk factors scheduled for coronary artery bypass surgery and in healthy blood donors. Periodontal pathogens were isolated by aerobic and anaerobic culture. RESULTS: All patients except one were < 55 yr of age and six were younger than 40 yr. Seropositivity to C. pneumoniae was significantly higher in CAD patients than healthy controls (63.3 vs. 23.3%, P<0.01). Combined seropositivity to both C. pneumoniae and M. pneumoniae was significantly higher in CAD patients with myocardial infarction (MI) than those without MI (61.5 vs. 11.8%, P<0.05). Aerobic and anaerobic cultures for the isolation of periodontal pathogens were positive in seven patients and five healthy blood donors. INTERPRETATION & CONCLUSION: C. pneumoniae seropositivity was significantly higher (P<0.001) in CAD patients without any of the conventional risk factors for CAD. Combined seropositivity to C. pneumoniae and M. pneumoniae was significantly higher (P<0.05) in CAD patients with MI than in those without MI. Possibly CAD in young is not (or less) governed by conventional risk factors, and infectious agents can be potential risk factors for the development of atherosclerosis and CAD in this subset of patients.

Myocardial injury in coronary artery bypass grafting: On-pump versus off-pump comparison by measuring heart-type fatty-acid-binding protein release.

This prospective study uses heart-type fatty-acid-binding protein (hFABP) and creatine kinase-MB (CK-MB) release to compare myocardial injury in on-pump versus off-pump coronary artery bypass grafting (CABG). Fifty patients were randomly assigned to on-pump or off-pump CABG. The hFABP and CK-MB concentrations were measured in serial venous blood samples drawn before heparinization in both groups and after aortic unclamping at 1, 2, 4, 8, 24, 48, and 72 hours in the on-pump group. In the off-pump group, samples were taken after the last distal anastomosis at the same time intervals as in the on-pump group. The total amount of hFABP and CK-MB released was significantly higher in the on-pump than in the off-pump group (hFABP = 100.43 +/- 77.63 vs 3.94 +/- 0.36 ng/mL, P < 0.0001; CK-MB = 33.33 +/- 3.81 vs 28.65 +/- 3.91 log units, P < 0.001). In all patients, hFABP levels peaked as early as 1 hour after declamping (on-pump group) or 2 hours after the last distal anastomosis (off-pump group), whereas CK-MB peaked only at 4 hours after declamping (on-pump group) or 24 hours after the last distal anastomosis (off-pump group). The lower release of hFABP and CK-MB in the off-pump CABG group indicates that on-pump CABG with cardioplegic arrest causes more myocardial damage than does off-pump CABG. Heart-type fatty-acid-binding protein is a more rapid marker of perioperative myocardial damage, peaks earlier than CK-MB, and may predict the requirement for intensive monitoring for postoperative myocardial infarction.

A comparative study of release of interleukin-6 and tumour necrosis factor during normothermic and hypothermic cardiopulmonary bypass.

The institution of cardiopulmonary bypass generates many pro-inflammatory cytokines and several clinical variables, including temperature, have been shown to influence cytokine release during and after cardiopulmonary bypass. The release of tumour necrosis factor and interleukin-6 are the best predictors of post-cardiopulmonary bypass related morbidity. Their release during normothermic and hypothermic cardiopulmonary bypass and the correlation with clinical parameters of organ injury was studied. This prospective study was carried out in 52 adult patients, scheduled for cardiac surgery, exposed to normothermic and 27 to hypothermic cardiopulmonary bypass. Samples for estimation of tumour necrosis factor and interleukin-6 were collected preoperatively, 1 hour and 24 hours post cardiopulmonary bypass and analysed by ELISA. Haemodynamic parameters and respiratory parameters were noted and lung injury scores calculated. Interleukin-6 levels were raised in both the groups at 1 hour and 24 hours post cardiopulmonary bypass and the response was higher in the normothermic group. Tumour necrosis factor response was, however, similar in both the groups, with a rise at 1 hour returning back to baseline by 24 hours post cardiopulmonary bypass. The normothermic group had a better respiratory index in the postoperative period, early extubation was possible, had better clinical haemodynamics, a shorter cardiopulmonary bypass time and had reduced requirement of defibrillation after the release of aortic cross clamp. We conclude that the release of interleukin-6 was thermo-dependent but did not correlate with the clinical signs of organ injury. Tumour necrosis factor levels were significantly raised after the cardiopulmonary bypass but the rise was not thermo-dependent.