Ultrasound detection of insulin-induced lipohypertrophy in Type 1 and Type 2 diabetes

Differences in clinicopathological characteristics between lipohypertrophy and localized insulin-derived amyloidosis: A scoping review

Insulin is used as a therapeutic agent in patients with diabetes, and cutaneous lipohypertrophy (LH) and localized insulin-derived amyloidosis (LIDA) are well-known adverse effects associated with insulin injections. The clinical implications, management, assessment methods, and pathological differentiation of LH and LIDA have been recently updated. This review was to update our knowledge of the pathological differentiation, effects of insulin absorption, hypoglycemic events, and recent assessment methods for LH and LIDA. A scoping review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta Analyses extension for Scoping Reviews guidelines. Original studies and case reports in English were also included. PubMed and Scopus databases were searched for keywords to identify papers published up to January 2022. A total of 113 studies were identified through a database search, and 31 were eligible for inclusion in this scoping review. In the 31 studies included in this review, patients with type 2 diabetes had high frequencies of LH and LIDA. LH outcome parameters were assessed using pathological findings and imaging. LIDA is mainly determined by pathological methods, such as hematoxylin and eosin and Congo red staining. Several in vitro and in vivo LIDA models of LIDA have been developed. These results suggest that pathological analysis is required to identify LH and LIDA. It is important to consider LIDA, as it likely influences insulin adsorption and glycemic control. Although several studies have evaluated the LIDA process, little is known about the mechanisms underlying the development of adverse effects associated with insulin injections.

A Hypothesis on the Progression of Insulin-Induced Lipohypertrophy: An Integrated Result of High-Frequency Ultrasound Imaging and Blood Glucose Control of Patients

AIMS

To put forward a scientific hypothesis about the progression of insulin-injection-induced lipohypertrophy (LH) according to the high-frequency ultrasonic imaging of insulin injection sites and the blood glucose control of patients.

METHODS

A total of 344 patients were screened for LH by means of high-frequency ultrasound scanning. The results of their ultrasound examination were described in detail and categorized into several subtypes. Seventeen patients with different subtypes of LH were followed up to predict the progression of LH. To further verify our hypothesis, the effects of different types of LH on glycemic control of patients were observed by comparing glycated hemoglobin A1c (HbA_1C) and other glycemic-related indicators.

RESULTS

LH was found in 255 (74.1%) patients. According to the high-frequency ultrasonic imaging characteristics, LH can be categorized into three subtypes in general. Among all the LHs, the most common type observed was nodular hyperechoic LH (n = 167, 65.5%), followed by diffuse hyperechoic LH (n = 70, 27.5%), then hypoechoic LH (n = 18, 7.0%). At the follow-up after six months, all 10 patients with nodular hyperechoic LH had LH faded away. Of the five patients with diffuse hyperechoic LH, two had inapparent LH, and three had diffuse hyperechoic parts which had shrunk under ultrasound. No obvious changes were observed in the two cases of hypoechoic LH. Compared with the LH-free group, the mean HbA_1C of the nodular hyperechoic LH group increased by 0.8% (9 mmol/mol) (95% CI:-1.394~-0.168, p = 0.005), that of the diffuse hyperechoic LH group increased by 2.0% (21 mmol/mol) (95% CI: -2.696~-1.20, p < 0.001), and that of the hypoechoic LH group increased by 1.5% (16 mmol/mol) (95% CI: -2.689~-0.275, p = 0.007).

CONCLUSIONS

It was hypothesized that the earlier stage of LH is nodular hyperechoic LH. If nodular LH is not found in time and the patient continues to inject insulin at the LH site and/or reuse needles, LH will develop into a diffuse type or, even worse, a hypoechoic one. Different subtypes of LH may represent differences in severity when blood glucose control is considered as an important resolution indicator. Further studies are needed to confirm our hypothesis on the progression and reversion of insulin-induced lipohypertrophy.

Lipohypertrophy and Insulin. An Old Dog that Needs New Tricks

OBJECTIVE

To review the current status of practical knowledge related to insulin-associated lipohypertrophy (LH) - an accumulation of fatty subcutaneous nodules commonly caused by repeated injections and/or infusions of insulin into the same site.

METHODS

Review of published literature with additional contributions from leading multidisciplinary experts with the emphasis on clinical aspects including pathophysiology, clinical and economic consequences, diagnosis, prevention and treatment.

RESULTS

LH is the most common dermatologic complication of insulin therapy. Risk factors for the development of lipohypertrophy include repeated delivery of large amounts of insulin into the same location over time, repeated injection trauma to the skin and subcutaneous tissue, and multiple injections using the same needle. Subcutaneous insulin injection in skin areas with lipohypertrophy is associated with reduced pain; however, this problem can interfere with insulin absorption, thereby increasing the likelihood of glucose variability, hypo- and hyperglycemia when a site is changed. Modern visualization technology of the subcutaneous space with ultrasound can demonstrate lipohypertrophy early in the course of its development.

CONCLUSIONS

The physiological and psychological consequences of developing insulin lipohypertrophy can be prevented and treated with education focusing on insulin injection techniques.

Type 1 Diabetes Mellitus and Lipohypertrophy - Impact of the Intervention on Glycemic Control via Patient's Examination and Retraining on Change of Infusion Set

OBJECTIVE

Lipohypertrophy (LH) is a common complication of insulin therapy in type 1 diabetes mellitus (T1DM). We examined whether an intervention consisting of LH assessment and retraining on insulin infusion set use improves glycemic control on subcutaneous insulin infusion (CSII) in patients with T1DM.

METHODS

The intervention was conducted in 79 consecutive patients with T1DM. Data on glucose levels, glycated hemoglobin (HbA1c), and insulin doses were collected at baseline and after a median of 22 weeks (20-31.75 weeks).

RESULTS

A total of 46 patients with T1DM (23 [50%] women) participating in the follow-up were characterized by a median age of 29 years (25-33.8 years), body mass index of 24.6 ± 3.3 kg/m², T1DM duration of 16.5 years (8.3-20 years), and subcutaneous insulin infusion duration of 7 years (4-10.8 years). Patients' median HbA1c fell from 7.4% (6.7%-8.2%) to 7.05% (6.4%-7.6%) (P < .001), daily insulin dose/kg decreased (0.7 ± 0.20 vs 0.68 ± 0.15 IU/kg; P = .017) together with the total daily insulin dose (50.3 [40.5-62.7] vs 47.6 [39.8-62.1] IU; P = .019]. Furthermore, the percentage of basal insulin dose increased (43.0% [36-50] vs 44.0% [39.0-50.0]; P = .010], whereas the percentage of bolus dose decreased (57% [50-64] vs 56% [50-61], P = .010).

CONCLUSIONS

The structured LH-related intervention in patients with T1DM on insulin pumps resulted in better glycemic control and a decrease in total daily insulin dose.

Evaluation of Lipohypertrophy in Patients With Type 1 Diabetes Mellitus on Multiple Daily Insulin Injections or Continuous Subcutaneous Insulin Infusion

OBJECTIVE

To determine lipohypertrophy (LH) in patients with type 1 diabetes mellitus (T1DM) on multiple daily insulin injections (MDII) or continuous subcutaneous insulin infusion (CSII) and to reveal the factors associated with the development and severity of LH.

METHODS

Sixty-six patients with T1DM treated with MDII (n = 35, 53%) or CSII (n = 31, 47%) for at least 1 year were included. LH localizations were detected with palpation and ultrasonography (USG).

RESULTS

The LH detection rate with USG was significantly higher than that by palpation in the whole group (P < .001). The LH was detected with USG in 30 (85.7%) patients in the MDII group and 22 (71.0%) patients in the CSII group (P = .144). Advanced LH was detected in 13 (37.1%) of the patients treated with MDII and in 3 (9.7%) of the patients treated with CSII. LH was more severe in the MDII group than in the CSII group (P = .013). Diabetes duration and length of infusion set use were significantly longer and body mass index, hypoglycemia, and complication rates were higher in patients with LH than those in patients without LH (P < .05). A positive correlation was found between LH severity and HbA1C and insulin dose (P < .05, for both). MDII as insulin administration method, incorrect rotation, and a history of ketosis were found to be the most related factors with LH severity in a multiple linear regression analysis (P < .05).

CONCLUSION

USG might be an effective approach for detecting and evaluating the severity of LH. MDII might cause more severe LH than CSII in patients with T1DM. In this study, LH was found to be associated mostly with incorrect rotation technique and a history of ketosis.

Why Do So Many People with Type 2 Diabetes Who Take Insulin Have Lipohypertrophy? Fate or Educational Deficiencies?

INTRODUCTION

Cutaneous lipohypertrophy (LH) is a thickened, "rubbery" lesion in the subcutaneous tissue following multiple injections performed at the same site, i.e., an incorrect injection technique. It is widespread, averaging 47% of insulin patients worldwide, and has severe direct and indirect consequences. Direct consequences consist mainly of poor metabolic control and frequent hypoglycemic events (HYPOs), and indirect ones of markedly increased healthcare costs related to hospital access due to acute events and long-term disease complications. This observation also holds for Italy, despite the National Health System organization expecting every patient with diabetes to undergo a series of visits by different care team members, each performing a specific treatment/education task. Indeed, the recent literature points to poor awareness of LH relevance and metabolic consequences among doctors from general and diabetic hospital wards, with educational deficiencies on correct injection practice in nurses too. The aim was to establish if, to what extent, and by whom they had received training on correct insulin injection techniques, and how many initially received notions had persisted over time.

METHODS

We investigated the possible causes of such a failure from the point of view of 1160 insulin-requiring subjects with type 2 diabetes (T2DM), reporting for the first time to specialized diabetic structures through a validated questionnaire and, in the same patients, we searched for LH by inspection/palpation according to international guidelines, further confirmed by ultrasound scans. We then analyzed differences in education and injecting behavior between subjects classified as LH+ or LH- depending on the presence or absence of LH lesions.

RESULTS

We documented significant educational gaps, with 50% of patients failing to refer to healthcare professionals and relying on their peers with diabetes, thought to be more experienced in 15% of the cases. Seventy-five percent of LH- patients received education from healthcare providers, while 90% of LH+ learned from another patient or could not remember how they knew, and 68% of LH+ versus 52% of LH- (p < 0.01) patients had failed to receive training on injection techniques by healthcare providers. All of this enabled the most disabling features of diabetes from the very beginning of the disease history.

CONCLUSIONS

This study documents, from the patients' point of view, that educational gaps are significant and that, even in initially trained subjects, education on correct injection techniques has a fleeting effect if not regularly recalled. Therefore, to rehabilitate LH+ patients as soon as possible and prevent LH- patients from inadvertently slipping into the other group, there is an urgent need to educate doctors and nurses repeatedly on the importance of correctly injecting insulin to improve patients' knowledge and skills.

Repeated insulin injection without site rotation affects skin thickness - ultrasonographic and histological evaluation

AIMS/INTRODUCTION

The influence of repeated insulin injection on subcutaneous tissue is known, but its impact on the skin is unclear. Therefore, this study aimed to elucidate the impact of repeated insulin injections on the skin.

MATERIAL AND METHODS

The properties of the skin and the subcutaneous tissue were evaluated in 52 insulin-treated adult patients with diabetes with abnormal findings at the site of self-injection (36 with subcutaneous nodules, 16 with suspected subcutaneous tissue induration) by ultrasonography. In all subjects, both normal and abnormal areas were examined. In addition, skin biopsies were performed in four subjects.

RESULTS

The skin thickness of the normal and abnormal skin sites was 1.95 (1.60, 2.50) and 2.80 (2.27, 3.30) mm, respectively (median (first quartile, third quartile)), (P < 0.001). The biopsy specimens revealed slightly thickened and tight bundles of collagen in the dermis. Three patients had amyloid deposits in the subcutaneous tissue, and one also showed these in the dermis. These were positively stained for insulin antibody.

CONCLUSIONS

Repeated insulin injection procedures result in skin thickening. Increased collagen fibers and possibly amyloid deposition in the dermis may be involved. The results reaffirmed the importance of appropriate site rotation in insulin injection and revealed the usefulness of ultrasonographic skin examination in evaluating the self-injection procedure.

Determination of insulin-related lipohypertrophy frequency and risk factors in patients with diabetes

INTRODUCTION

Insulin, which is used in the treatment of diabetes mellitus (DM), may lead to the development of lipohypertrophy (LH) which can negatively affect the management of diabetes mellitus. Two common methods to detect LH are palpation and superficial subcutaneous ultrasonography (SSU). We investigated the frequency of non-palpable LH using SSU, as well as examining risk factors.

METHOD

We included in our study patients who had been receiving insulin injections at least twice a day for over one year without palpable LH. The epidermis and the subcutaneous tissue thickness of each region were examined using SSU. The presence of LH and associated risk factors for LH were evaluated.

RESULTS

We included 136 patients in our study. The mean age of all patients was 52.87±14.93 years, 59.6% were female and 73.5% had type 2 DM. The duration of DM and insulin usage were 15.76±9.20 and 11.42±8.26 years, respectively. The mean body mass index (BMI) of all patients was 30.59±7.40kg/m². Non-palpable LH was detected in 87.5% (n=116) of the patients using SSU. In the multivariate logistic regression analyses, total cholesterol level, short-acting insulin dose and coronary artery disease (CAD) were associated with LH presence.

CONCLUSION

Non-palpable LH can be seen at high rates in patients who have multiple insulin injections. Palpation is likely not enough to detect LH and we believe it would be appropriate to evaluate the presence of LH using SSU, especially for those who need high-dose insulin to control hyperglycaemia.

Machine Learning Decision Support for Bedside Ultrasound to Detect Lipohypertrophy

BACKGROUND

The most common dermatological complication of insulin therapy is lipohypertrophy.

OBJECTIVE

As a proof-of-concept, we built and tested an automated model using a convolutional neural network (CNN) to detect the presence of lipohypertrophy in ultrasound images.

METHODS

Ultrasound images were obtained in a blinded fashion using a portable GE LOGIQe machine with an L8-18i-D probe (5-18 MHz; GE Healthcare, Frankfurt, Germany). The data was split into train, validation and test splits of 70%, 15%, and 15% respectively. Given the small size of the dataset, image augmentation techniques were used to expand the size of the training set and improve the model's generalizability. To compare the performance of the different architectures, the team considered the accuracy and recall of the models when tested on our test set.

RESULTS

The DenseNet CNN architecture was found to have the highest accuracy (76%) and recall (76%) in detecting lipohypertrophy in ultrasound images, when compared to other CNN architectures. Additional work showed that the YOLOv5m object detection model could be used to help identify the approximate location of lipohypertrophy in ultrasound images identified as containing lipohypertrophy by the DenseNet CNN.

CONCLUSIONS

We were able to demonstrate the ability of machine learning approaches to automate the process of detecting and locating lipohypertrophy.

CLINICALTRIAL

Insulin-induced Lipohypertrophy in Patients with Type 1 Diabetes Mellitus Treated with an Insulin Pump

BACKGROUND

Lipohypertrophy (LH) of subcutaneous tissue is an insulin-induced complication occurring in patients with diabetes. We aimed to define the prevalence of LH and identify its risk factors in type 1 diabetes (T1DM) patients treated with continuous subcutaneous insulin infusion (CSII).

MATERIALS AND METHODS

The study included 79 consecutive CSII-treated T1DM patients. The diagnose of LH was based on ultrasonography (US) as a reference method, physical examination was also performed. Clinical characteristics were available from the medical records.

RESULTS

The median age of patients was 28 years (interquartile range [IQR], 24-30.5) with a body mass index (BMI) of 24.5 ± 3.5 kg/m², HbA_1c 7.1% (IQR, 6.7-8.1), T1DM duration 15 (9-20) years, and CSII use duration of 8 year (IQR, 5-11). LH was detected by US in 75 (94.9%) patients. This value was much higher than this obtained by visual assessment (n = 39, 49.4%) or palpation (n = 59, 74.7%). In univariate analyses, the following risk factors for occurrence of 5 and more LH lesions were identified: the ratio of insulin dose to body mass exceeding 0.7 IU/kg (OR, 3.69; 95% CI, 1.43-10.01) and the total daily insulin dose (OR, 1.05; 95% CI, 1.02-1.09). A higher dose of insulin per kg remained a significant risk factor of LH amount in multivariate analysis.

CONCLUSION

This selected T1DM cohort treated with CSII had a very high prevalence of LH. US assessment should be considered as a reference method for LH screening in T1DM patients. The identified risk factors for the number of LH lesions were related to insulin dosing.

A Systematic Survey of Physicians' Insights Into Lipohypertrophy

Background: It is important that physicians be aware of LH. We designed a questionnaire to determine physician awareness, knowledge, and behaviors regarding LH in clinical practice.

Participants: A total of 499 questionnaires were completed by physicians in hospitals from 13 cities in Jiangsu Province, China.

Key Results: Compared with physicians at tertiary hospitals, significantly fewer physicians at primary hospitals reported awareness of LH and its screening methods. The proportion of resident physicians aware of LH was significantly lower than the proportion of senior physicians. The proportion of physicians who could identify all LH risk factors among the low-GDP group was significantly higher than the high-GDP group. Only 38.7% of doctors could successfully identify all the hazards associated with LH, but more doctors in tertiary hospitals were able to do so compared to those in secondary and primary hospitals. Compared with tertiary hospitals, the proportions of primary and secondary hospitals with management processes were significantly lower. The proportion of doctors who educated patients regarding LH prevention and treatment in primary hospitals was markedly lower than in tertiary hospitals.

Conclusions: Overall, physicians have an inadequate understanding of LH, especially in primary hospitals.

Characteristics and morphology of lipohypertrophic lesions in adults with type 1 diabetes with ultrasound screening: an exploratory observational study

INTRODUCTION

Lipohypertrophy is a common complication of exposure to insulin therapy. Despite the prevalence of lipohypertrophy and its potentially hazardous effects on glucose regulation, it remains a relatively understudied problem in diabetes. The objective of this study was to characterize lipohypertrophic tissue using ultrasound in adults with type 1 diabetes.

RESEARCH DESIGN AND METHODS

An observational study of 74 people with type 1 diabetes from a diabetes center in South East London. Participants' insulin exposed areas were scanned with ultrasound, with a high-frequency linear probe (6-13 MHz). The observed tissue changes were described, measured and graded according to nodule size and thickness of the dermal layer.

RESULTS

Participants mean age and diabetes duration were 40.6 (±14.2) and 18.3 (±10.9) years, respectively, and 60% (n=44) were male. A total of 740 lipohypertrophic nodules were observed, ranging from 1.8 mm to 40 mm in width. The mean (SD/range) number of nodules per participants was 10.4 (±6.2/1-29). Delineation between the dermal layers was disrupted in all current injection sites. In 52 participants (70%), there was a 30% increase in dermal thickness compared with local none injected tissue, and in 36 participants (48%) the increase was 50%. The level of thickness was >3 mm in the abdominal areas of 22 (40%) of these participants and in thighs of eight participants (17.8%). Hypoechogenic areas suggestive of necrotic tissue were observed within the lipohypertrophic nodules of 22 (30%) participants. Needle length and nodule depth were correlated (r=0.69, p<0.001). A conceptual model of the insulin exposed tissue changes observed was constructed.

CONCLUSIONS

The study confirms that insulin-exposed tissue changes are heterogenous and has provided conceptual and grading frameworks for classifying these changes. Further studies are required to establish the clinical implications of these classifications, in relation to glucose regulation and other clinical parameters.

Determination of insulin-related lipohypertrophy frequency and risk factors in patients with diabetes

INTRODUCTION

Insulin, which is used in the treatment of diabetes mellitus (DM), may lead to the development of lipohypertrophy (LH) which can negatively affect the management of diabetes mellitus. Two common methods to detect LH are palpation and superficial subcutaneous ultrasonography (SSU). We investigated the frequency of non-palpable LH using SSU, as well as examining risk factors.

METHOD

We included in our study patients who had been receiving insulin injections at least twice a day for over one year without palpable LH. The epidermis and the subcutaneous tissue thickness of each region were examined using SSU. The presence of LH and associated risk factors for LH were evaluated.

RESULTS

We included 136 patients in our study. The mean age of all patients was 52.87±14.93 years, 59.6% were female and 73.5% had type 2 DM. The duration of DM and insulin usage were 15.76±9.20 and 11.42±8.26 years, respectively. The mean body mass index (BMI) of all patients was 30.59±7.40kg/m2. Non-palpable LH was detected in 87.5% (n=116) of the patients using SSU. In the multivariate logistic regression analyses, total cholesterol level, short-acting insulin dose and coronary artery disease (CAD) were associated with LH presence.

CONCLUSION

Non-palpable LH can be seen at high rates in patients who have multiple insulin injections. Palpation is likely not enough to detect LH and we believe it would be appropriate to evaluate the presence of LH using SSU, especially for those who need high-dose insulin to control hyperglycaemia.

Values of ultrasound for diagnosis and management of insulin-induced lipohypertrophy: A prospective cohort study in China

The aim of this study was to explore the values of ultrasound for diagnosis and management of insulin-induced lipohypertrophy and further analyzing the impact of body mass index and subcutaneous fat thickness on ultrasound manifestations of lipohypertrophy.In this 3-month, prospective cohort study, a total of 162 patients with diabetes who used insulin therapy more than 1 year with unknown lipohypertrophy status were enrolled into this study. Demographic information, assessment of glycemic control and insulin injection technique were evaluated. Physical and ultrasound examination were separately performed to detect lipohypertrophy by a team of diabetes educator nurses or ultrasonographer in a blinded fashion. Patients with lipohypertrophy received insulin injection technique education based on ultrasound examination and Chinese guideline.Ultrasound examination detected 41.1% more patients (74.1% vs 52.5%; P < .001) with lipohypertrophy and 61.2% more lesions (216 vs 134; P < .001) than physical examination. Glycosylated hemoglobin A1c and fasting blood glucose were significantly decreased in patients with lipohypertrophy or subclinical lipohypertrophy (lipohypertrophy without visual and palpation changes) after receiving insulin injection technique education based on ultrasound examination and Chinese guideline than baseline at 3 months (P < .001). The proportion of lesions with ultrasound manifestation 2 (distortion of surrounding connective tissue) in obese and STF (>15 mm) groups were no more than 50% and showed a decreased trend with increased subcutaneous fat thickness and body mass index (P < .001).Lipohypertrophy has characteristic ultrasound manifestations which can detect more accurate results than palpation alone and provide detailed information to promote effective education on lipohypertrophy management, thereby improving glycemic control.

A meta-analysis and meta-regression on the prevalence of lipohypertrophy in diabetic patients on insulin therapy

AIMS OF THE STUDY

This study aimed to assess the prevalence of lipohypertrophy (LH) in diabetes mellitus (DM) patients on insulin therapy and identify factors influencing the prevalence rates through a meta-analysis and meta-regression.

METHODS

Databases of PubMed, Embase, Scopus, and Google Scholar were screened from inception to 20th Aug 2020. Data on prevalence was transformed using the logit transformation for pooling the proportions using the DerSimonian-Laird meta-analysis model. Random-effects meta-regression analysis was performed to assess the influence of the following moderators on the pooled prevalence: male gender, mean age, type of DM, DM duration, duration of insulin therapy, needle re-users, rotation of injection site, HbA_1c, insulin dose, ≥8mm needle users and mean number of injections/day.

RESULTS

Forty-five studies were included. LH was diagnosed by observation and palpation by all studies. On meta-analysis of data from 26,865 participants, the overall prevalence of LH was found to be 41.8% (95% CI: 35.9% to 47.6%). On region-wise analysis, pooled prevalence of LH in Europe was 44.6% (95% CI: 37.5% to 51.8%) in Africa was 34.8% (95% CI: 16.9% to 52.8%) and in Asia was 41.3% (95% CI: 27.2% to 55.3%). The pooled prevalence of LH in studies only on type 1 and type 2 DM patients was 39.9% (95% CI: 28.3% to 51.6%) and 45.9% (95% CI: 29.5% to 62.4%) respectively. Only insulin duration was found to significantly influence the prevalence of LH on meta-regression.

CONCLUSION

Our study indicates that the prevalence of LH in DM patients on insulin therapy is estimated to be 41.8%. The longer the duration of insulin therapy, the higher is the prevalence of LH.

Point-of-Care Ultrasound (POCUS) in the Field of Diabetology

Ultrasound is increasingly used in daily clinical practice to improve the efficiency of the clinical examination. In this article, we reviewed its various possible uses in the field of diabetology. The ultrasonic evaluation of the carotid arteries (plaques and intima media thickness) allows improving the assessment of the cardiovascular risk. Steatosis can be detected relatively easily on liver ultrasound. Ultrasound also allows a more sensitive detection of lipohypertrophy resulting in glycemic fluctuations and thus increasing the risk of hypoglycemia than the clinical examination. Finally, muscle ultrasound appears to be a promising tool to assess the nutritional status and its consequences (e.g., falls).

Subclinical lipohypertrophy--Easily ignored complications of insulin therapy

AIMS

Subclinical lipohypertrophy is a lesion meeting ultrasonic criteria for lipohypertrophy that was not detected by inspection and palpation. Little information is published on subclinical lipohypertrophy among insulin injection people with diabetes. We aimed to investigate the subclinical lipohypertrophy prevalence, risk factors, and the association between subclinical lipohypertrophy and glycemic control.

METHODS

This observational study included 316 people with diabetes who had continuously received insulin therapy for at least one year. We performed ultrasound scanning and clinical examination for evidence of subclinical lipohypertrophy. Demographic characteristics, clinical information, and glycated hemoglobin were measured.

RESULTS

The overall prevalence of subclinical lipohypertrophy was 19.9%. By stepwise logistic regression, higher BMI (OR = 1.44, 95%CI: 1.15-1.81, P = 0.002), incorrect rotation of sites (OR = 3.11, 95%CI: 1.02-9.47, P = 0.046), insulin needle reusage for more than four times (OR = 10.00, 95%CI: 3.23-31.02, P = 0.000) and type 1 diabetes (OR = 6.33, 95%CI: 1.32-30.47, P = 0.021) remained associated with subclinical lipohypertrophy. Subclinical lipohypertrophy demonstrated a significant independent correlation with the nonoptimal glycemic control (OR = 9.97, 95% CI: 3.46-28.75, P = 0.000) when accounting for demographic and diabetes-related parameters.

CONCLUSIONS

Subclinical lipohypertrophy is common among insulin-injecting patients with diabetes and is related to glycemic control deterioration. Ultrasonography may be an ideal adjunct in the evaluation of easily ignored lipohypertrophy lesions, especially where poor glycemic control, incorrect injection behaviors, overweight or obesity are documented.

Prevalence, Risk Factors, and Clinical Characteristics of Lipodystrophy in Insulin-Treated Patients with Diabetes: An Old Problem in a New Era of Modern Insulin

BACKGROUND

Lipodystrophy has been reported as a common complication in insulin-treated patients, which could lead to unexplained hypoglycemia and suboptimal glycemic control. This study aimed to determine the prevalence, associated risk factors, and clinical characteristics of insulin-induced lipodystrophy in Thai patients.

PATIENTS AND METHODS

This was a cross-sectional study involving insulin-treated patients at Theptarin Hospital, one of the largest diabetes centers in Thailand.

RESULTS

A total of 400 patients were studied (female 53.5%, T2DM 86%, mean age 65.6±15.4 years, duration of diabetes 23.0±10.2 years, median insulin treatment 10 years, usage of insulin analog 72.1%, A1C 7.9±1.6%) . The prevalence of lipohypertrophy (LH) in overall patients was 37.3% (T1DM 46.4% and T2DM 35.8%). The highest prevalence (57.5%) was observed in long-standing (≥10 years) T1DM patients. Multivariate analysis revealed that the duration of insulin use (≥10 years), use of human insulin, and incorrect rotation of injection sites were associated with LH. Patients with LH were found to have 7-times greater risk of unexplained hypoglycemia when compared with patients without LH. Lipoatrophy (LA) was found in only four cases (1.0%). All LA cases had a concurrence palpable area of LH.

CONCLUSION

Insulin-induced lipodystrophy is still an overlooked complication in the conundrum of diabetes care. The presence of lipodystrophy was significantly associated with the occurrence of unexplained hypoglycemia. It should be emphasized to recognize this condition by inspecting and palpating insulin injecting sites regularly, and educate patients to avoid the development of lipodystrophy.