Lipohypertrophy risks of injecting repeatedly to the same area

[chriskchris]

Came across this term for a condition caused by repeat injections to the same spot. Seems mostly applicable to diabetics who do daily injections but I am running out of tricks as to why my test-c lost efficiency.

I have been injecting to the same area in the thigh for 5-years now. I don't see any lumps but wonder if there could be less absorption due to this?

Anybody ever experience this conditions with their testosterone injections?

 

[tareload]

Came across this term for a condition caused by repeat injections to the same spot. Seems mostly applicable to diabetics who do daily injections but I am running out of tricks as to why my test-c lost efficiency.

I have been injecting to the same area in the thigh for 5-years now. I don't see any lumps but wonder if there could be less absorption due to this?

Anybody ever experience this conditions with their testosterone injections?

Lipohypertrophy: Symptoms, Causes, Treatment & Prevention

Lipohypertrophy is a lump of fatty tissue under your skin caused by repeated injections in one area. It’s common in people who need insulin injections for diabetes.

my.clevelandclinic.org

Modified absorption parameters? Sure.

Less absorption? Doubtful. Any evidence for this? I am not aware of any. I'll take a look.

 

[tareload]

Impaired Absorption of Insulin Aspart From Lipohypertrophic Injection Sites

Lipohypertrophy is a common side effect of subcutaneous insulin therapy, occurring in up to 50% of patients with type 1 diabetes (1–3). It is generally hel

diabetesjournals.org

Interesting results. Differenr Cmax and AUC in the LT tissue for insulin.

You would need to invoke same argument for decreased absorption mechanism (degradation) with Tcyp which would be a stretch in my mind.

Thanks for the fun topic.

 

[tareload]

Factors Affecting the Absorption of Subcutaneously Administered Insulin: Effect on Variability

Variability in the effect of subcutaneously administered insulin represents a major challenge in insulin therapy where precise dosing is required in order to achieve targeted glucose levels. Since this variability is largely influenced by the absorption of insulin, a deeper understanding of the...

www.hindawi.com

4.5. Lipodystrophy​

Repeated injections of insulin into the same skin area can induce lipodystrophic changes in the SC tissue [160, 161]. Lipodystrophy comprises both lipoatrophy and lipohypertrophy, and its prevalence is highest in children and young patients with type 1 diabetes [168, 169]. Lipoatrophy is believed to be caused by immunological factors, and—as with insulin antibodies—its prevalence has been significantly reduced since the availability of more purified insulin preparations and the introduction of recombinant human insulin and insulin analogues [169]. Hence, we will only review the clinical impact of lipohypertrophy in this section.

Lipohypertrophy is believed to be a nonimmunological side effect caused by the anabolic potential of insulin, occurring irrespective of administration route [7, 169, 170]. In a recent study, the prevalence of lipohypertrophy was reported to be as high as 76% and 56% in people with type 1 and type 2 diabetes, respectively [160]. Although lipohypertrophy is not believed to be caused by immunological factors, insulin antibody titres have been reported to correlate with the degree of lipoatrophy and lipohypertrophy in young people with type 1 diabetes [171]. However, a direct role of insulin antibodies in the pathogenesis of lipohypertrophy has still not been established [170].

Compared to normal SC tissue, the SC tissue in lipohypertrophied areas is more fibrous and has a poorer blood supply. Consequently, lipohypertrophy is associated with delayed insulin absorption, reduced bioavailability (potentially due to a higher degree of local degradation), and increased pharmacokinetic variability between injections [137, 138, 168]. One study conducted in people with type 1 diabetes showed that compared to injection of insulin aspart into normal abdominal tissue, injection into lipohypertrophied tissue resulted in a 25% and 22% decrease in insulin and 4-hour insulin exposure (AUC0–4h), respectively [138]. Similar results have been reported for NPH injected into the thigh region and human insulin injected into abdomen, thigh, or deltoid [139, 140]. Repeated injection of insulin lispro into lipohypertrophic areas has been reported to result in increased variability between injections in certain pharmacokinetic and pharmacodynamic parameters in patients with type 1 diabetes [137]. Here, the coefficients of variation (CVs) for AUC0–4h and were as high as 52% and 55% upon injection into lipohypertrophic areas compared to 11% and 15% upon injection into normal SC tissue. Consequently, the variability in 4 h glucose exposure (AUCGIR0–4h) was also higher with injection into lipohypertrophic areas reflected by CVs of 57% compared to 23% in normal tissue. Others have also reported lipohypertrophy to be associated with higher prevalence of hypoglycaemia and increased glucose variability (blood glucose readings above or below 13.9 and 3.3 mM, respectively, at least three times a week) [160]. Thus, besides being perceived as an aesthetical problem, lipohypertrophy can increase pharmacokinetic variability between injections if patients repeatedly inject into these areas or rotate between lipodystrophy-affected and unaffected injection sites.

Reported risk factors for development of lipodystrophy include BMI, injection technique, number of injections per day, duration of treatment, size of the area usually used for injection, and frequency of changing injection sites and needles [160, 161, 169]. Unfortunately, many patients prefer to inject insulin into lipodystrophic tissue, since pain sensation is lower in these areas, although it worsens the condition [169]. While rotation of injection sites is highly preventive in the development of lipodystrophy [160, 161, 168], this procedure will increase the pharmacokinetic variability between injections, as mentioned earlier [131]. A compromise is therefore recommended consisting of systematic rotation within one region in order to both prevent development of lipodystrophy while simultaneously reducing the pharmacokinetic variability associated with random injection into different regions [86, 141] (Table 4). Consequently, although reducing the intraregional variability in insulin absorption due to a reduced number of injections, the use of insulin pumps may increase the incidence of lipodystrophy due to reduced capacity to rotate injection sites [170].