Comment on the New Indian Injection Technique Recommendations: Critical Appraisal of the Real-World Implementation of the Current Guidelines

This article is based on previously published investigations and does not involve any new studies of human or animal subjects performed by the authors.

Even though some 90 years have passed since insulin was first commercialized, a fairly large number of patients are still not using an appropriate injection technique. Moreover, although advances in technology have made new syringes, pens, and increasingly short, thin, and sharp needles available, insulin treatment has not yielded the expected results—many issues have not yet been resolved, and there are still too many unmet needs. As a matter of fact, only half of all insulin-treated patients reach their therapeutic targets worldwide [3], so it is crucial that insulin is routinely injected into healthy subcutaneous tissue.

The factors involved in nonoptimal and quite often unpredictable insulin absorption have been identified during the last 10 years or so [4‐6]: (1) the use of overlong needles; (2) frequent needle reutilization; (3) failure to systematically rotate injection sites; (4) missed skinfold pinching/45° angle needle injection in thin people; (5) failure to systematically inspect/palpate LH skin nodules before injections; (6) patient underestimation of guidelines on correct insulin injection; (7) a lack of preliminary structured education concerning the best injection modalities; (8) missed regular patient refresher courses; and (9) a lack of regular nurse examinations at which skin lesions and/or inappropriate injection modalities are identified. Indeed, these bad habits are widespread, and have been addressed by several scientific publications [6], including regularly issued guidelines and expert recommendations suggesting practical solutions for correcting behavior. However, LH is still frequent and is associated with clinical consequences, including poor metabolic control [7, 8], severe hypoglycemic episodes, and high health/social costs [9].

In addition, injections are often painful, thus reducing compliance to treatment. Therefore, to try to prevent pain and simplify the injection technique, shorter (4- and 5-mm) needles have been developed and commercialized and careful training is recommended. Nevertheless, patients and nurses still often use 8-mm needles which exceed the thickness of the skin and subcutaneous fat and thus penetrate into the muscle. This is bound to cause poor glycemic control [7, 8], as discussed in greater detail in the next paragraph.

Over the last few decades, it has become increasingly apparent that body structure, funding, and the availability of updated devices or next-generation insulins vary markedly among International Diabetes Federation (IDF) member regions.

As far as skin and subcutaneous tissue (SCT) structure is concerned, several studies have highlighted that the average BMI is lower in adult or infant Asians than in the ROW [1, 2, 10‐14] (especially in Europeans [15‐19]), as well as the existence of a positive correlation between SCT thickness and BMI. Because the skin and subcutaneous adipose layer are relatively thin in subjects with a low BMI, they are at a high risk for accidental intramuscular injections [10‐14]. Considering the multiethnicity of Western societies, it is important to take this issue into account in Western populations.

In an ultrasound evaluation of an adult Chinese population [11], skin thickness showed only a minimal dependence on body site and on various demographic characteristics (including age, gender, type of diabetes, and BMI), whereas SCT appeared to be far more variable: its thickness was greater in women, at the abdominal level, and in patients with a high BMI. Studies of skin and SCT thicknesses in other Asian populations, such as Filipinos [12], Koreans [13], and Indians [14], yielded comparable results to those obtained for the Chinese population, whereas non-Asian populations had considerably higher BMIs in a major ultrasound-based study [16, 17].

Lower BMI values may also have contributed to the popularity of shorter insulin needles, as Indian patients become aware of the risks of IM injections with longer needles when the BMI is low.

Recent studies of a large population of adults with diabetes found that the skin thickness at the insulin injection site differed minimally with patient characteristics such as the BMI (i.e., obese patients had similar skin thicknesses to normal and thin patients) [13, 20]. However, the same study showed that fat thickness (SC space) varied widely from one individual to another based on gender, BMI, and injection area. It highlighted the risk of IM injections, and showed that 4-mm needles presented the lowest risk of such injections. A study recently published in India confirmed those findings [16].

The other important issue that is raised by the papers from Indian authors [1, 2] is that real-life injection habits do not match the guidelines published in many countries, especially the latest recommendations published by the panel of experts attending the 2015 FITTER Congress in Rome [20]. Economic factors work against clinically appropriate solutions, as repeated reuse of the same needle is a widespread habit in Indian patients. That said, this practice appears to be highly prevalent worldwide due to not only financial constraints but also a dangerous mix of ignorance, opportunism, and laziness indulged in by both patients and operators. In everyday practice, structured education appears to be hardly (if ever) performed, as reported by a large number of both Indian [1, 2, 14] and Italian [16‐18] patients. Sadly, there are also no guidelines suggesting how related knowledge should be reinforced by appropriate educational follow-up sessions that also give health care providers a chance to verify the injection habits of individual patients. Moreover, although professional educators are available for this purpose in several countries, in other countries doctors and nurses acting as self-learners often attempt to improvise the role of expert educators; after providing their patients with superficial information, they do not plan any periodic refresher or quality control sessions. The result is a widespread lipodystrophic phenomenon [7] and a high rate of seemingly inexplicable hypoglycemia and high glycemic variability that are closely related to poor injection techniques, which could eventually be prevented or reversed by experienced structured educational activities [7, 19, 21].