Accuracy of CGM Systems During Continuous and Interval Exercise in Adults with Type 1 Diabetes

BACKGROUND

continuous glucose monitoring systems (CGMs) play an important role in the management of T1D, but their accuracy may reduce during rapid glucose excursions. The aim of study was to assess the accuracy of recent rt-CGMs available in Italy, in subjects with T1D during 2 sessions of physical activity: moderate continuous (CON) and interval exercise (IE).

METHOD

we recruited 22 patients with T1D, on CSII associated or integrated with a CGM, to which a second different sensor was applied. Data recorded by CGMs were compared with the corresponding plasma glucose (PG) values, measured every 5 minutes with the glucose analyzer. To assess the accuracy of the CGMs, we evaluated the Sensor Bias (SB), the Mean Absolute Relative Difference (MARD) and the Clarke error grid (CEG).

RESULTS

a total of 2355 plasma-sensor glucose paired points were collected. Both average plasma and interstitial glucose concentrations did not significantly differ during CON and IE. During CON: 1. PG change at the end of exercise was greater than during IE (P = .034); 2. all sensors overestimated PG more than during IE, as shown by SB (P < .001) and MARD (P < .001) comparisons. Classifying the performance according to the CEG, significant differences were found between the 2 sessions in distribution of points in A and B zones.

CONCLUSIONS

the exercise affects the accuracy of currently available CGMs, especially during CON, suggesting, in this circumstance, the need to maintain blood glucose in a "prudent" range, above that generally recommended. Further studies are needed to investigate additional types of activities.

Is cardiorespiratory fitness impaired in PCOS women? A review of the literature

PURPOSE

Polycystic ovary syndrome (PCOS) is a common and heterogeneous endocrine disorder, affecting 8-12% of reproductive-aged women. Insulin resistance and body fat excess are common features in these subjects. Increased physical activity and diet modifications are the first recommended approach in the management of these women, at least in overweight/obese subjects. Evaluation of cardiorespiratory fitness (CRF) is important in assessing exercise performance and in monitoring the effects of physical exercise interventions. Several studies have shown that CRF may be impaired in metabolic and endocrine disorders. However, there are little data on this issue in PCOS women. The aim of this narrative review is to critically evaluate whether aerobic capacity is altered in PCOS women, focusing on maximal oxygen uptake.

METHODS

An updated search of the literature was performed, identifying papers with maximal oxygen consumption measurements in women with PCOS compared to healthy controls.

RESULTS

We have identified six studies on this specific topic: four of them showed an alteration of maximal oxygen consumption in PCOS women, whereas two did not. However, taken together these studies suggest that CRF may be strikingly impaired in both normal-weight and overweight/obese subjects with this condition.

CONCLUSIONS

Women with PCOS appear to be characterized by a reduced cardiopulmonary fitness. However, further research on this topic is needed. This information may hopefully help clinicians and exercise specialist in planning individualized exercise programs aimed at improving the metabolic and endocrine outcomes in these women.

Reduced lymphocyte subpopulations in patients with advanced or disseminated melanoma

BACKGROUND

Studies have revealed many features of lymphocyte behavior in patients with malignant melanoma, but there are conflicting results.

OBJECTIVE

The aim of this study was to measure with easily reproducible assays the circulating lymphocytes and other immunologic aspects in 33 patients with advanced or disseminated malignant melanoma (MM).

METHODS

The following variables were measured: circulating monocytes; total lymphocytes; B (CD19) and T-cell subpopulations; CD3, CD4, and CD8, natural killer cells (anti-Leu-7+ or CD57 and anti-Leu-11+ or CD16) (cytofluorimetry); plasma levels of IgG, IgA, IgM, and IgE; complement fractions 3, 4, and 1Q; antibodies against foreign microorganisms (AaM) (adeno, herpes simplex, herpes zoster, measles, parotitis, cytomegalo, Epstein-Barr, and rubella viruses) and Toxoplasma; and cutaneous delayed hypersensitivity (CDH) to recall antigens (tetanus, diphtheria, Streptococcus, tuberculin, Proteus, Trichophyton, and Candida). We also studied 96 healthy persons, matched for age and geographic location, who were tested on the same days as the patients.

RESULTS

In MM the number of total lymphocytes and subsets CD19, CD3, CD4, and CD8 was decreased from 25% to 40% (p < 0.001). The CD4/CD8 ratio increased (22%, p < 0.005) because of the relatively greater decrease of CD8. The CD57 and CD16 cells (expression of natural killer lymphocytes) were consistently reduced (30%; p < 0.002 to p < 0.003). C3 serum level was increased (30%; p < 0.001). Immunoglobulins, CDH, AaM, and all other tests were the same in the two groups.

CONCLUSION

The single most important result seems to be a reduction of CD57 and CD16 cells in patients with advanced MM.