Can we check serum lithium levels less often without compromising patient safety?

BACKGROUND

Lithium is viewed as the first-line long-term treatment for prevention of relapse in people with bipolar disorder.

AIMS

This study examined factors associated with the likelihood of maintaining serum lithium levels within the recommended range and explored whether the monitoring interval could be extended in some cases.

METHOD

We included 46 555 lithium rest requests in 3371 individuals over 7 years from three UK centres. Using lithium results in four categories (<0.4 mmol/L; 0.40-0.79 mmol/L; 0.80-0.99 mmol/L; ≥1.0 mmol/L), we determined the proportion of instances where lithium results remained stable or switched category on subsequent testing, considering the effects of age, duration of lithium therapy and testing history.

RESULTS

For tests within the recommended range (0.40-0.99 mmol/L categories), 84.5% of subsequent tests remained within this range. Overall, 3 monthly testing was associated with 90% of lithium results remaining within range, compared with 85% at 6 monthly intervals. In cases where the lithium level in the previous 12 months was on target (0.40-0.79 mmol/L; British National Formulary/National Institute for Health and Care Excellence criteria), 90% remained within the target range at 6 months. Neither age nor duration of lithium therapy had any significant effect on lithium level stability. Levels within the 0.80-0.99 mmol/L category were linked to a higher probability of moving to the ≥1.0 mmol/L category (10%) compared with those in the 0.4-0.79 mmol/L group (2%), irrespective of testing frequency.

CONCLUSION

We propose that for those who achieve 12 months of lithium tests within the 0.40-0.79 mmol/L range, the interval between tests could increase to 6 months, irrespective of age. Where lithium levels are 0.80-0.99 mmol/L, the test interval should remain at 3 months. This could reduce lithium test numbers by 15% and costs by ~$0.4 m p.a.

Comparison of two live-animal ultrasound systems for genetic evaluation of carcass traits in Angus cattle

The improvement of carcass traits is an important breeding objective in beef cattle breeding programs. The most common way of selecting for improvement in carcass traits is via indirect selection using ultrasound scanning of selection candidates which are submitted to genetic evaluation programs. Two systems used to analyze ultrasound images to predict carcass traits are the Pie Medical Esaote Aquila (PIE) and Central Ultrasound Processing (CUP). This study compared the ability of the two systems to predict carcass traits for genetic evaluation in Australian Angus cattle. Genetic and phenotypic parameters were estimated using data from 1,648 Angus steers which were ultrasound scanned twice with both systems, first at feedlot entry and then following 100 d in the feedlot. The traits interpreted from ultrasound scanning included eye muscle area (EMA), rib fat (RIB) rump fat (RUMP), and intramuscular fat (IMF). Abattoir carcass data were collected on all steers following the full feedlot feeding period of 285 d. For all ultrasound scan traits, CUP resulted in higher phenotypic and genetic variances compared to the PIE. For IMF, CUP had higher heritability at feedlot intake (0.51 for CUP compared to 0.37 for PIE) and after 100 d feeding (0.54 for CUP compared to 0.45 PIE). CUP predicted IMF also tended to have stronger correlations with the breeding objective traits of carcass IMF and marbling traits, both genetically (ranging from 0.59 to 0.75 for CUP compared to 0.45–0.63 for PIE) and phenotypically (ranging from 0.27 to 0.43 for CUP compared to 0.19–0.28 for PIE). Ultrasound scan EMA was the only group of traits in which the heritabilities were higher for PIE (0.52 for PIE compared to 0.40 for CUP at feedlot intake and 0.46 for PIE compared to 0.43 for CUP at 100 d of feeding), however with similar relationships to the breeding objective carcass EMA observed. For subcutaneous fat traits of ultrasound RIB and RUMP, the heritabilites and genetic correlations to the related carcass traits were similar, with the exception being the higher heritability observed for CUP predicted RUMP at feedlot intake at 0.52 compared to 0.38 for PIE. The results from this study indicates that the CUP system, compared to PIE, provides an advantage for genetic evaluation of carcass traits in Angus cattle, particularly for the IMF and associated marbling traits.

People with Type Diabetes Mellitus (T1DM) self-reported views on their own condition management reveal links to potentially improved outcomes and potential areas for service improvement

BACKGROUND

The self-management of type 1 diabetes (T1DM) has moved forward in many areas over the last 40 years. Our study asked people with T1DM what is their experience of blood glucose (BG) monitoring day to day and how this influences decisions about insulin dosing.

METHODS

An on-line self-reported questionnaire containing 44 questions prepared after consultation with clinicians and patients was circulated to people with T1DM 116 responders provided completed responses. Fixed responses were allocated specific values (e.g. not confident = 0 fairly confident = 1). Multivariate regression analysis was carried out. Only those 5 factors with p-value <0.05 were retained.

RESULTS

59% of respondents were >50 years old and 66% had diabetes for >20 years, with 63% of patients reporting HbA1c results ≤8% or 64 mmol/mol. Findings included; 75% used only 1 m; 56% had used the same meter for ≥3 years; 10% had tried flash monitors; 47% were concerned about current BG level; 85% were concerned about long-term impact of higher BG. 72% of respondents keep BG level high to avoid hypoglycaemia; 25% used ≥7 mmol/L as pre-meal BG target to calculate dose; 65% were concerned they might be over/under-dosing; 83% did not discuss accuracy when choosing meter. However 85% were confident in their meter's performance. The factors that linked to LOWER HbA1c included LESS units of basal insulin (p < 0.001), HIGHER number of daily BG tests (p = 0.008), LOWER bedtime blood glucose (p = 0.009), HIGHER patient's concern over long-term impact of high BG (BG) (p < 0.009 but LOWER patient's concern over current BG values (p = 0.009). The final statistical model could explain 41% of the observed variation in HbA1c.

CONCLUSION

Many people still run their BG high to avoid hypoglycaemia. Concern about the longer-term consequences of suboptimal glycaemic control was associated with a lower HbA1c and is an area to explore in the future when considering how to help people with T1DM.