Socioeconomic inequities in invasive cardiac procedures after first myocardial infarction in Finland in 1995

OBJECTIVE: We examined socioeconomic disparities in coronary procedure rates after first events among hospitalized myocardial infarction (MI) patients. STUDY DESIGN AND SETTING: Information on MI patients in 1995 in Finland was obtained from the Finnish Cardiovascular Disease Register Project. Data on comorbidity, invasive treatments, hospitalizations, mortality, and socioeconomic status were obtained by linking data from the Finnish Hospital Discharge Register, cause of death register, population census, and the health insurance register using personal identity numbers. RESULTS: In 1995, 5172 patients aged 40 to 74 years were hospitalized for first MI. This corresponds to age-standardized event rates of 354/100,000 for men and 152/100,000 for women. Within 2 years, 33% of men and 21% of women underwent an invasive coronary procedure. Men in the lowest income third underwent 25% (95% confidence interval [CI] 12-36) fewer procedures than men in the highest third. Among women, the corresponding difference was 43% (95% CI 24-57). These disparities persisted throughout the 2-year follow-up, and they were not reduced by adjustment for comorbidity or hospital district. CONCLUSION: Socioeconomic disparities were observed in receipt of invasive cardiac procedures. More attention should be paid to equitable distribution of scarce health care resources.     

Peripheral neuropathy in late onset spinocerebellar ataxia

We studied 10 patients with late onset spinocerebellar ataxia including electrophysiological and muscle biopsy examinations. Nerve conduction studies of eight patients revealed axonal neuropathy, and six cases also showed signs of the involvement of the lower motor neuron. In 9 patients quantitative analysis of single motor unit potentials (MUPs) of the tibialis anterior or biceps brachii muscles showed mild to severe neuropathic changes and in all 10 patients the histopathological examination of the tibialis anterior showed mild to severe neuropathic changes. Neither nerve conduction studies, quantitative MUP analysis, nor histological findings of the muscle were related to the severity of duration of the disease.     

The association of Acetyl-l-Carnitine with glucose and lipid metabolism in human muscle in vivo: The effect of hyperinsulinemia

We examined whether hyperinsulinemia is associated with changes in the amount of l-carnitine and acetyl-l-carnitine in the muscle and whether the source of acetyl-coenzyme A (CoA) (glucose or free fatty acids [FFAs]) influences its further metabolism to acetyl-l-carnitine or through tricarboxylic acid in the skeletal muscle of man in vivo. Twelve healthy men (aged 45 ± 2 years; body mass index, 25.2 ± 1.0 kg/m²) were studied using a 4-hour euglycemic-hyperinsulinemic clamp (1.5 mU/kg/min) and indirect calorimetry. Although the mean muscle free l-carnitine and acetyl-l-carnitine concentrations remained unchanged during hyperinsulinemia in the group as a whole, the individual changes in muscle free l-carnitine and acetyl-l-carnitine concentrations were inversely related (r = −.72 P < .02). The basal level of acetyl-l-carnitine was inversely related to the rate of lipid oxidation (r = −.70 P < .02). In a stepwise linear regression analysis, 77% of the variation in the change of acetyl-l-carnitine concentrations was explained by the basal muscle glycogen level (inversely) and nonoxidative glucose disposal rate (directly) during hyperinsulinemia (P < .01); by adding the final FFA concentration (inverse correlation) to the model, 88% of the variation was explained (P < .001). In conclusion, (1) hyperinsulinemia does not enhance skeletal muscle free l-carnitine or acetyl-l-carnitine concentrations in man, and (2) the acetyl group of acetyl-l-carnitine in human skeletal muscle in vivo is probably mostly derived from glucose and not through β-oxidation from fatty acids.     

Median nerve somatosensory evoked potentials during isoflurane anaesthesia

Purpose

The effect of isoflurane on the subcortical P₁₄ component of the median nerve somatosensory evoked potential (SEP) is poorly known. We studied whether the P₁₄ wave from the upper brainstem, recorded with a nasopharyngeal electrode, was attenuated at the isoflurane-induced EEG burst-suppression level. We also compared the effect of isoflurane on the P₁₄, cervical N₁₃ and cortical N₂₀, N₃₅ and N₆₀ components.

Methods

Seventeen elective patients were anaesthetized with isoflurane. Somatosensory evoked potentials were recorded pnor to anaesthesia, at 0.5 MAC and I MAC end-tidal isoflurane as well as at the level when EEG was in burst-suppression (mean 1.9 vol% end-tidal isoflurane).

Results

Isoflurane had varying effects on the subcortical components of median SEP. The amplitude of nasopharyngeal P₁₄ was stable, but the mean latency increased from 14.4 ± 1.2 msec at 0.5 MAC to 15.2 ± 1.1 msec at burstsuppression level (P < 0.05). In contrast, the N₁₃ neck response amplitude was attenuated from 3.3 ± 0,6 μV to 2.6 ±0.5μV (P < 0.005) without latency changes. The latency of the cortical N₂₀ wave was increased from 19.7 ± 1.1 msec at awake to 24.4 ± 1.6 msec at burst-suppression level (P < 0.0001) and amplitude was reduced from 3.3 ± 1.1 μV to 1.3 ± 0.6 μV (P < 0.0001). The later cortical components were attenuated even during 0.5 MAC isoflurane and were not recordable during EEG burst-suppression.

Conclusion

We conclude that P₁₄ can reliably be recorded with nasopharyngeal electrodes during isoflurane anaesthesia, even during EEG burst-suppression, when the N₂₀ wave is attenuated. In contrast, the middle-latency SEP components are sensitive to isoflurane anaesthesia.     

Cardiorespiratory responses to fatiguing dynamic and isometric hand-grip exercise

In occupational work, continuous repetitive and isometric actions performed with the upper extremity primarily cause local muscle strain and musculoskeletal disorders. They may also have some adverse effects on the cardiorespiratory system, particularly, through the elevation of blood pressure. The aim of the present study was to compare peak cardiorespiratory responses to fatiguing dynamic and isometric hand-grip exercise. The subjects were 21 untrained healthy men aged 24–45 years. The dynamic hand-grip exercise (DHGE) was performed using the left hand-grip muscles at the 57 (SD 4)% level of each individual's maximal voluntary contraction (MVC) with a frequency of 51 (SD 4) grips · min^−l. The isometric hand-grip exercise (IHGE) was done using the right hand at 46 (SD 3)% of the MVC. The endurance time, ventilatory gas exchange, heart rate (HR) and blood pressure were mea- sured during both kinds of exercise. The mean endurance times for DHGE and IHGE were different, 170 (SD 62) and 99 (SD 27) s, respectively (P < 0.001). During DHGE the mean peak values of the breathing frequency [20 (SD 6) breaths · min⁻¹] and tidal volume [0.89 (SD 0.34) l] differed significantly (P < 0.01) from peak values obtained during IHGE [15 (SD 5) breaths · min⁻¹, and 1.14 (SD 0.32) l, respectively]. The corresponding peak oxygen consumptions, pulmonary ventilations, HR and systolic blood pressures did not differ, and were 0.51 (SD 0.06) and 0.46 (SD 0.11) l · min⁻¹, 17.1 (SD 3.0) and 16.7 (SD 4.7) l · min⁻¹, 103 (SD 18) and 102 (SD 17) beats · min⁻¹, and 156 (SD 17) and 161 (SD 17) mmHg, respectively. The endurance times of both DHGE and IHGE were short (<240 s). The results indicate that the peak responses for the ventilatory gas exchange, HR and blood pressure were similar during fatiguing DHGE and IHGE, whereas the breathing patterns differed significantly between the two types of exercise. The present findings emphasize the importance of following ergonomic design principles in occupational settings which aim to reduce the output of force, particularly in tasks requiring isometric and/or one-sided repetitive muscle actions. Accepted: 16 February 2000