#536 - Continuous Glucose Monitors, Gout Update, Haven’t Got Time
Take 3 – Practical Practice Pointers©
From the Literature
1) Continuous Blood Glucose Monitoring
The indications for continuous glucose monitoring (CGM) have broadened from Type 1 diabetes only to now include Type 2 diabetes (T2DM). The evidence for improved glycemic control has been established for type 1 diabetes but has been inconsistent in Type 2. There are three types of CGM:
- real-time (rt) CGM, where users get continuous updates of their glucose levels,
- retrospective (or professional) CGM, where glucose levels are recorded continuously, but the patient does not see the readings until they are downloaded after a week or two (this review does not address these), and
- intermittent scan (is) CGM, where patients must manually wave a reader over the sensor to obtain data.
The authors of a new systematic review in the American Diabetes Association’s journal Diabetes Care wanted to summarize the available evidence for CGMs in T2DM. They performed a reasonably comprehensive search, had explicit inclusion criteria which included a requirement of at least 8 weeks of use of the CGM. Change in hemoglobin A1c (HgbA1c) was the primary outcome, and there were several other lab and clinical outcomes listed as secondary. Studies were evaluated with the Cochrane Risk of Bias tool and they appropriately assessed heterogeneity in the study data.
Twenty-nine articles were found about 26 studies. There were 17 trials of rtCGM and 9 trials of isCGM both vs. self-measured blood glucose (SMBG) readings by fingerstick. The articles were generally at low risk of bias. The range of baseline HgbA1c was 6.6 to 9.9% and the rest of the patients seemed appropriately diverse with respect to age and medications.
For rtCGM, there was a drop of -0.19% (95% confidence interval (CI) -0.34 to -0.04%) and for isCGM, there was a drop of -0.31% (95% CI -0.46 to -0.17%) both compared to usual care/SMBG. These results did not vary by time of treatment, treatment type, baseline A1c level or other factors. There were no changes in body weight or other clinical outcomes. Small groups of included studies showed some additional benefit for isCGM over rtCGM on “time in range” of blood glucoses. In terms of safety, both rtCGM and isCGM had more device and all-cause adverse events, but not glucose-related adverse events. Patients’ satisfaction scores were better than SMBG with isCGM and worse than SMBG with the rtCGM. The authors note the limitations of lack of standardization in outcomes across the included studies as well as the short duration of CGM use (8-34 weeks). All the authors have received funding from various device manufacturers and other industry sources, but state that the study design and reporting were not influenced by industry.
The ADA standards of care recommend CGM use (either type, but they rate the evidence better for rtCGM) for patients with type 2 diabetes who are on multiple daily insulin injections or a single basal insulin injection. They recommend, based on expert opinion only, CGM for youth with type 2 diabetes if they are capable of using it correctly.
John’s Comments:
The authors also note that this is a rapidly involving field of both technology and evidence, so conclusions like safety can change rapidly as the technology improves; do not interpret these findings as settled evidence. Noting the better results from isCGM than rtCGM reminds me a lesson we encounter repeatedly in medicine – that more information is not always better than just some information. It may be that the requirement to actively swipe the monitor in isCGM leads to more attention to blood sugar levels. For now, the evidence points most strongly to using isCGM in patients on insulin who are capable of using it correctly and safely.
References:
- Seidu S, Kunutsor SK, Ajjan RA, Choudhary P. Efficacy and Safety of Continuous Glucose Monitoring and Intermittently Scanned Continuous Glucose Monitoring in Patients With Type 2 Diabetes: A Systematic Review and Meta-analysis of Interventional Evidence. Diabetes Care. 2024;47(1):169-179. Link
- American Diabetes Association Professional Practice Committee. 7. Diabetes Technology: Standards of Care in Diabetes—2024. Diabetes Care. 2023;47(Supplement_1):S126-S144. Link
From the Literature and the American College of Rheumatology (ACR)
2) Gout Refresher
Gout is the most common form of inflammatory arthritis, affecting more than 12 million adults in the US. Acute gout is caused by accumulation of monosodium urate crystallization in the joints, typically due to chronic hyperuricemia, with serum urate levels exceeding the saturation point of approximately 6.8 mg/dL for monosodium urate crystallization in the body. While the etiology of gout is well-understood and there are effective and inexpensive medications to treat it, gaps in quality of care persist. A treat-to-target management strategy that includes urate lowering therapy (ULT) dose titration measurements to achieve and maintain a target serum urate (SU) level of <6mg/dl is strongly recommended by the American College of Rheumatology (ACR) for over 2 decades. Despite this, there has been no increase in ULT utilization. Adherence to ULT remains poor as well.
How much does “treating to target” matter? A recently published retrospective study using the UK Biobank data base assessed the associations of a single serum urate measurement with subsequent risk of acute gout flares among patients in the UK with a history of gout. Among 3613 patients with gout (mean age, 60 years; 3104 [86%] men), over a mean follow-up of 8.3 years, 95% of gout flares occurred in people with baseline serum urate > 6 mg/dL and 98% got those with a baseline serum urate greater > 5. Rates of acute gout flares per 1000 person-years were 10.6 for participants with urate levels < 6, 40.1 for levels of 6.0 to 6.9 mg/dL, 82.0 for levels of 7.0 to 7.9 mg/dL, 101.3 for levels of 8.0 to 8.9 mg/dL, and > 120 for urate levels > 9. So it appears maintaining lower serum urate levels matters to prevent acute flares.
In 2020, the American College of Rheumatology (ACR) published updated guidelines for the treatment of gout. Below are some pertinent reminders:
- Initiating pharmacologic urate lowering therapy (ULT) is strongly recommended for gout patients with any of the following: ≥1 subcutaneous tophi; evidence of radiographic damage (any modality) attributable to gout; OR frequent gout flares, with frequent being defined as ≥ 2 annually and conditionally recommended for patients who have previously experienced >1 flare but have infrequent flares (<2/year).
- Initiating ULT is conditionally recommended for patients with experiencing their first flare when comorbid moderate-to-severe CKD (stage ≥3), SU concentration >9 mg/dl, or urolithiasis is present.
- Initiating ULT is conditionally recommended against in patients with asymptomatic hyperuricemia. (NNT – 24 to prevent 1 flare over 3 years)
- Treatment with the xanthene oxidase inhibitor allopurinol as the preferred first-line agent, over all other ULTs, is strongly recommended for all patients, including those with moderate-to-severe CKD (stage ≥3).
- Starting treatment with low-dose allopurinol (≤100 mg/day and lower in patients with CKD [stage ≥3]) with subsequent dose titration is strongly recommended.
- Administering concomitant anti-inflammatory prophylaxis therapy (e.g., colchicine, nonsteroidal anti-inflammatory drugs, prednisone/prednisolone) over no anti-inflammatory prophylaxis therapy is strongly recommended.
- Continuing concomitant anti-inflammatory prophylaxis therapy for 3–6 months over <3 months, with ongoing evaluation and continued prophylaxis as needed if the patient continues to experience gout flares, is strongly recommended.
- Continuing ULT indefinitely over stopping ULT is conditionally recommended.
- Switching hydrochlorothiazide to an alternate antihypertensive when feasible is conditionally recommended for patients with gout, regardless of disease activity.
- Using NSAIDS, colchicine, or glucocorticoids (oral, intraarticular, or intramuscular) as appropriate first-line therapy for gout flares is strongly recommended.
- Given similar efficacy and a lower risk of adverse effects, low-dose colchicine (no more than 1.8 mg/day on day 1, then 0.6 mg qd/bid subsequently) over high-dose colchicine is strongly recommended when colchicine is the chosen agent.
- When the decision is made that ULT is indicated while the patient is experiencing a gout flare, starting ULT during the gout flare over starting ULT after the gout flare has resolved is conditionally recommended.
Mark’s Comments:
The ACR has been consistent in their guidance to treat to target with allopurinol for most patients who are candidates for gout treatment. Though recommended for quite some time, my experience is that most patients who are started on medication are not followed-up for serum uric acid monitoring. Reframing recurrent gout as a chronic disease may help us think differently about how we treat and monitor it. A 1-month supply of allopurinol is presently < $10 and colchicine < $25 from GoodRx.
Note that if an NSAID is chosen for treatment, all prescription strength NSAIDs appear equally effective in optimum doses for treatment of acute gout and there are choices with a safer side-effect profile than indomethacin. Note as well that “pushing colchicine to diarrhea,” which some may have learned during their training, is discouraged.
Remember that when appropriate treatment is started within 24 hours of a flare, it will usually resolve in 2-3 days, whereas waiting will often result in the necessity of treating for a much longer period of time. This means we need to be educating our patients with recurrent gout to not wait to contact/see us prior to starting treatment and to be sure they have their medications available.
References:
From PeerRxMed ( www.PeerRxMed.org )
3) Practicing What We Profess: Haven’t Got Time?
“Why is it that giving myself a break feels like such a big deal!?” Me
For multiple reasons, it’s been a rough few weeks physically and emotionally for me. In the midst of that, I asked one of my PeerRx buddies, “Why is it that giving myself a break feels like such a big deal!?”
“Sounds like you need some self-compassion,” they replied with a smile. “Perhaps you need to go back and read your previous blog on that.” And then they challenged me, “Why don’t you just take a week off from writing a blog entry?”
While I couldn’t find a good reason, I did find a reason; “That’s just not what Mark does.”
They laughed, and replied, “Is it too late for Mark to change?”
My answer is contained in the poem below, written as a “message from my Soul” in response to my recent challenges. Where might you need to give yourself a break? If doing so seems like a “big deal,” consider the cost of not doing so. That’s likely a way bigger deal. It certainly has been for me. Here’s to making some regular time for self-compassion, and then remembering ….
Haven’t Got Time
“I haven’t got time for the pain,” she sang
like the voice on the radio
from long ago
though the music
was all in my head …
and as she continued,
I told my pain
neither do I
but the pain
didn’t seem
to care …
nor did
the
time.
“Suffering, was the only thing that
made me feel I was alive,”
she persisted ….
Fortunately a Voice
of self-compassion
interrupted,
encouraging me
yet once again
to recognize that
this background music,
now the soundtrack of
my present suffering,
was simply residual
noise from my past
and was no longer
enlivening … if it ever was ….
So I turned down the volume,
hoping this time
to remember,
until I next
forget
I really haven’t
got
time
.
.
.
______________
Mark and John
Carilion Clinic Department of Family and Community Medicine
Feel free to forward Take 3 to your colleagues. Glad to add them to the distribution list.
Email: mhgreenawald@carilionclinic.org