The antioxidant, tert-butylhydroquinone: a new cause of asthma

The antioxidant, tert-butylhydroquinone (TBHQ), a common additive in food and cosmetics can cause allergic contact dermatitis. A 49-year-old non-atopic male factory worker developed asthma in connection with cleaning mixing drums containing TBHQ. Due to the suspicion that TBHQ might be the cause of asthma, a specific inhalation challenge was carried out. Lactose was used as a control agent. The following day he developed asthma symptoms with a 41% drop in FEV1 after 30-min exposure to small amounts of TBHQ and water. Methacholine reactivity increased 5-fold after TBHQ exposure compared to pre-exposure reactivity. This suggests that TBHQ may be the cause of asthma in this case. Due to this case respirators were introduced in the factory to reduce TBHQ exposure. TBHQ has not previously been shown to cause asthma.

Delayed occupational asthma from epoxy exposure

BACKGROUND

A delayed asthma reaction occurring several hours after exposure is difficult to diagnose.

AIMS

To confirm a delayed asthma reaction in five workers following epoxy exposure.

CASE REPORT

Working conditions with exposure to epoxy encountered at the workplace were reproduced in a challenge chamber. Specific inhalation challenge (SIC) with epoxy was compared to a control challenge. All five cases had delayed a asthma response 6-15 h after epoxy exposure.

CONCLUSIONS

Our study confirms that SIC is a useful tool in diagnosing delayed asthma response.

Counter-regulatory hormone responses to spontaneous hypoglycaemia during treatment with insulin Aspart or human soluble insulin: a double-blinded randomized cross-over study

AIMS

To compare insulin Aspart and human insulin with respect to glycaemic control, hypoglycaemic frequency and counter-regulatory responses to spontaneous hypoglycaemia.

METHODS

Glycaemic control, hypoglycaemic frequency, p-insulin concentrations, insulin dosages and patients' satisfaction were examined in a randomized, double-blinded cross-over study for two periods of 8 weeks. Sixteen patients with type 1 diabetes were subjected to three daily injections of human soluble insulin or Aspart in addition to Neutral Protamine Hagedorn (NPH) insulin twice daily. Each intervention period was followed by hospitalization where episodes of spontaneous hypoglycaemia and counter-regulatory hormone responses were evaluated from frequently obtained blood samples.

RESULTS

No difference between soluble insulin and insulin Aspart was found regarding HbA1c (7.0 ± 0.2 vs. 7.0 ± 0.2%, ns), hypoglycaemic frequency (1.1 ± 0.2 vs. 0.9 ± 0.1 events per patient per week, ns), nocturnal hypoglycaemia, severe hypoglycaemic events, dosages of bolus insulin (31.8 ± 0.4 vs. 30.0 ± 0.6 IU day(-1), ns), or NPH insulin (26.7 ± 1.8 vs. 26.0 ± 1.7 IU day(-1) , ns) or in patients satisfaction (ns). Modest differences existed in the counter-regulatory responses regarding growth hormone, glucagon and ghrelin whereas no differences were found in relation to free fatty acid, cortisol, insulin-like growth factor (IGF)-I, IGF-II and IGF-binding proteins 1 and 2. Treatment with insulin Aspart resulted in well-defined peaks in serum insulin concentrations as compared with more blunted insulin peaks using human soluble insulin.

CONCLUSION

Although insulin Aspart treatment was associated with clear postprandial insulin peaks, no improvement in glycaemic control was obtained and no difference in the hypoglycaemic frequency was observed. However, insulin Aspart elicited a slightly different physiological response to spontaneous hypoglycaemia compared with human insulin.