Advancements in Insulin Therapy: Current Status and Future Directions

Feroze^*

Department of Research centre, Iran

Received: 05-June -2023, Manuscript No. jdmc-23-101381; Editor assigned: 08-June -2023, PreQC No. jdmc-23- 101381 (PQ); Reviewed: 23-June -2023, QC No. jdmc-23-101381; Revised: 27-June -2023, Manuscript No. jdmc-23-101381 (R); Published: 30-June -2023 DOI: 10.37532/ jdmc.2023.6(3).47-52

Abstract

Insulin therapy has revolutionized the treatment of diabetes, a chronic metabolic disorder characterized by impaired insulin production or utilization. This therapeutic approach aims to restore and maintain optimal blood glucose levels by supplementing or replacing the body’s deficient insulin supply. Over the years, insulin therapy has evolved from crude animal-derived preparations to highly purified human insulin and more recently to analog insulins with improved pharmacokinetic profiles. This abstract provides an overview of the principles and advancements in insulin therapy, including different insulin formulations, routes of administration, and delivery systems. The various insulin regimens, such as basal-bolus, multiple daily injections, and continuous subcutaneous insulin infusion, are discussed, along with their advantages and limitations. Additionally, factors influencing insulin requirements, such as individualized dosing, meal planning, physical activity, and coexisting medical conditions, are explored. Furthermore, the challenges associated with insulin therapy, such as hypoglycemia, weight gain, injection-related issues, and the psychological impact on individuals with diabetes, are addressed. Finally, emerging trends in insulin therapy, such as the development of closed-loop systems and the potential role of adjunctive therapies, are highlighted. Overall, insulin therapy remains a cornerstone in the management of diabetes, and continued research and technological advancements are essential to improve outcomes and enhance the quality of life for individuals living with this chronic condition.

Keywords

Insulin therapy• Meal planning• Psychological impact• Hypoglycemia• Weight gain

Introduction

Insulin therapy has revolutionized the treatment of diabetes, a chronic metabolic disorder characterized by impaired insulin production or utilization. Diabetes affects millions of individuals worldwide and is associated with significant morbidity and mortality if not properly managed. Insulin, a hormone produced by the pancreas, plays a central role in regulating glucose metabolism and maintaining optimal blood glucose levels. Therefore, the administration of exogenous insulin is crucial for individuals with diabetes who cannot produce or effectively utilize their own insulin. The concept of insulin therapy dates back to the early 20th century when the link between insulin deficiency and diabetes was discovered [1]. In 1921, Sir Frederick Banting and Charles Best successfully isolated and purified insulin from animal sources, marking a major breakthrough in the treatment of diabetes. The first human patient was treated with insulin in 1922, and since then, insulin therapy has been an indispensable tool in managing diabetes [2-5]. The primary objective of insulin therapy is to achieve and maintain tight glycemic control, as prolonged hyperglycemia can lead to various complications affecting multiple organ systems. By providing exogenous insulin, insulin therapy aims to mimic the physiological role of endogenous insulin, enabling glucose to enter cells for energy utilization and storage. This not only helps regulate blood glucose levels but also prevents the harmful effects of chronic hyperglycemia on blood vessels, nerves, and other tissues.

Over the years, insulin therapy has evolved significantly, driven by advances in pharmaceutical technology and a better understanding of diabetes pathophysiology. Initially, insulin was derived from animal sources, such as cows and pigs, leading to impurities and adverse reactions in some patients. However, with advancements in purification techniques, highly purified human insulin became available, reducing the risk of allergic reactions and improving treatment outcomes. More recently, the development of analog insulins has revolutionized insulin therapy [6]. Analog insulins are modified forms of human insulin with altered pharmacokinetic and pharmacodynamic properties, designed to more closely mimic physiological insulin secretion. These analogs offer improved glycemic control, reduced risk of hypoglycemia, and greater flexibility in dosing regimens. Rapid-acting analogs provide a faster onset of action and a shorter duration, better matching postprandial insulin requirements. Long-acting analogs provide a more prolonged and consistent effect, mimicking basal insulin secretion. Insulin therapy can be administered through various routes, including subcutaneous injections, insulin pens, insulin pumps, and inhalation devices. Subcutaneous injections are the most common method, involving the use of syringes or insulin pens to deliver insulin into the fatty tissue just beneath the skin [7,8]. Insulin pumps, on the other hand, provide a continuous subcutaneous infusion of insulin, mimicking the function of a healthy pancreas more closely. Inhalation devices deliver insulin directly to the lungs, offering a noninjectable alternative for those who are averse to injections. Different insulin regimens are employed based on individual needs and preferences. The basal-bolus regimen, also known as intensive insulin therapy, involves administering a long-acting insulin as a basal dose to provide a background insulin level throughout the day, while rapid-acting insulin is administered with meals to cover the postprandial rise in blood glucose. This regimen offers greater flexibility and tighter glycemic control. Multiple daily injections (MDI) involve administering a mixture of rapid-acting and intermediate-acting insulin before meals, typically done two to four times a day. MDI is an alternative to the basal-bolus regimen, offering simplicity and flexibility while still achieving reasonable glycemic control.

Insulin therapy has revolutionized the treatment of diabetes, a chronic metabolic disorder that affects millions of individuals worldwide. Diabetes is characterized by the body’s inability to regulate blood glucose levels properly, either due to insufficient production of insulin or impaired utilization of the hormone. Insulin, a hormone produced by the beta cells of the pancreas, plays a vital role in glucose metabolism by facilitating the uptake of glucose into cells and promoting its storage in the liver and muscles. In individuals with diabetes, the absence or inadequate action of insulin results in elevated blood glucose levels, leading to various complications and impairments in overall health [9].

The concept of insulin therapy was introduced in the early 20th century when the association between insulin deficiency and diabetes was discovered. In 1922, Sir Frederick Banting and Charles Best successfully isolated and purified insulin from animal sources, paving the way for the first therapeutic use of insulin in humans. This breakthrough discovery transformed the management of diabetes, providing a life-saving treatment option for individuals previously condemned to a grim prognosis. Since its inception, insulin therapy has undergone significant advancements, fueled by ongoing research and technological innovations. The early forms of insulin therapy involved the use of animal-derived insulin, which, although effective, posed challenges due to variations in purity, potency, and potential allergic reactions. With further advancements, the development of highly purified human insulin became possible, reducing the risk of complications associated with animal-derived insulin. In recent years, the focus of insulin therapy has shifted towards the development of analog insulins. Analog insulins are synthetic versions of human insulin designed to mimic the physiological actions of endogenous insulin more closely. These analogs offer improved pharmacokinetic profiles, providing better control over postprandial glucose levels and reducing the risk of hypoglycemia [10]. Rapidacting analogs have a faster onset of action and shorter duration, allowing for better matching of insulin delivery with meals. Longacting analogs provide a basal level of insulin over an extended period, offering more stable and consistent glucose control throughout the day. Insulin therapy encompasses various aspects, including insulin formulations, routes of administration, and delivery systems. Insulin formulations can be categorized based on their onset, peak, and duration of action, enabling healthcare providers to tailor treatment regimens to individual needs. The availability of insulin in different forms, such as vials, pens, and pumps, allows for flexibility and convenience in insulin administration, promoting adherence to therapy. Insulin regimens are designed based on individual requirements, taking into account factors such as age, lifestyle, comorbidities, and personal preferences. The most commonly used regimens include basalbolus therapy, multiple daily injections (MDI), and continuous subcutaneous insulin infusion (CSII) using insulin pumps [11]. Basal-bolus therapy involves the administration of basal insulin to provide a steady background level of insulin and bolus insulin before meals to cover the rise in blood glucose levels. MDI involves the use of a combination of rapid-acting and long-acting insulins injected multiple times a day. CSII, also known as insulin pump therapy, delivers a continuous basal rate of insulin with the flexibility of administering bolus doses as needed. In addition to insulin dosage and administration, various factors influence insulin requirements and overall glycemic control. These factors include individualized dosing based on blood glucose monitoring, carbohydrate counting or meal planning, physical activity, stress levels, and the presence of other medical conditions [12,13]. Each individual’s insulin needs may vary, necessitating regular monitoring and adjustments to optimize therapy.

Methods

Insulin therapy involves the administration of exogenous insulin to individuals with diabetes to regulate their blood glucose levels effectively. Various methods are available for delivering insulin, each with its advantages and considerations. The choice of method depends on factors such as individual needs, lifestyle, treatment goals, and healthcare provider recommendations. Here are the main methods for insulin therapy:

Subcutaneous injections

Subcutaneous injections are the most common and traditional method of delivering insulin. Insulin is injected into the fatty tissue just beneath the skin using insulin syringes or insulin pens. The injection sites commonly used include the abdomen, thighs, upper arms, and buttocks. Rotation of injection sites within the same general area is recommended to prevent lipodystrophy (thickened or lipoatrophy (thinned) areas of subcutaneous tissue) and ensure consistent absorption.

Insulin pens

Insulin pens are handheld devices that resemble writing pens and contain pre-filled insulin cartridges. They offer convenience and ease of use, especially for individuals who require multiple daily injections (MDI) [14,15]. Insulin pens are available in two types: disposable pens, which are discarded after the insulin cartridge is empty, and reusable pens, which allow for the replacement of insulin cartridges.

Insulin pumps

Insulin pumps are small electronic devices that deliver insulin continuously through a subcutaneous catheter. The pump is typically worn on the body, and insulin is delivered through a flexible tubing and infusion set. Insulin pumps provide both basal and bolus insulin, allowing for more precise control over insulin delivery throughout the day. The pumps can be programmed with different basal rates to match individual needs and can deliver additional bolus doses before meals or to correct high blood glucose levels. Continuous subcutaneous insulin infusion (CSII) using insulin pumps offers flexibility and can be particularly beneficial for individuals with variable insulin requirements or those who require small basal rates.

Inhalable insulin

Inhalable insulin provides an alternative to subcutaneous injections for mealtime insulin dosing. It involves inhaling powdered insulin through a handheld inhaler device. Inhalable insulin is a rapid-acting insulin and can be used in combination with long-acting insulin or oral medications for diabetes management. It offers a non-invasive method of insulin delivery and may be suitable for individuals who struggle with injections or have needle phobia. However, it is essential to note that inhalable insulin is not suitable for everyone, and it is crucial to discuss its use with healthcare providers.

Intravenous insulin

Intravenous (IV) insulin therapy is used in specific situations, such as during hospitalization or in critical care settings. It involves the continuous infusion of insulin directly into a vein using an IV pump. Intravenous insulin allows for precise control of blood glucose levels and is often used when rapid adjustments in insulin doses are required. It is important to note that the method of insulin delivery is only one aspect of insulin therapy. Insulin dosage, timing, and individualized treatment regimens play a crucial role in achieving optimal glycemic control. Regular monitoring of blood glucose levels, close communication with healthcare providers, and adherence to recommended insulin therapy guidelines are essential for successful insulin management.

Individuals considering or already using insulin therapy should consult with their healthcare providers to determine the most appropriate method of insulin delivery based on their specific needs and preferences. Regular follow-up and adjustments to insulin therapy may be necessary to achieve and maintain target blood glucose levels and minimize the risk of complications associated with diabetes.

Results

Insulin therapy is a cornerstone in the management of diabetes and has demonstrated significant benefits in improving glycemic control and reducing the risk of complications associated with diabetes. Here are some key results and outcomes associated with insulin therapy:

Glycemic control

Insulin therapy aims to achieve and maintain target blood glucose levels. By providing exogenous insulin, insulin therapy helps regulate blood glucose and prevents hyperglycemia (high blood sugar) episodes. Improved glycemic control is associated with reduced risks of acute complications, such as diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS).

Prevention of long-term complications

Consistent and effective insulin therapy has been shown to reduce the risk of long-term complications related to diabetes. These complications include cardiovascular disease, neuropathy (nerve damage), nephropathy (kidney damage), retinopathy (eye damage), and lower limb complications. Maintaining stable blood glucose levels through insulin therapy helps mitigate the damage caused by sustained hyperglycemia.

Enhanced quality of life

Insulin therapy enables individuals with diabetes to better manage their condition, leading to an improved quality of life. By controlling blood glucose levels, insulin therapy helps alleviate symptoms associated with high blood sugar, such as excessive thirst, frequent urination, fatigue, and blurred vision. Stable blood glucose levels contribute to overall well-being and allow individuals to engage in daily activities without disruption.

Individualized Treatment

Insulin therapy can be tailored to meet individual needs and preferences. Healthcare providers work closely with individuals with diabetes to determine the most appropriate insulin regimen, dosage, and timing. This personalized approach ensures that insulin therapy aligns with each person’s lifestyle, optimizing adherence and overall treatment outcomes.

Improved Diabetes Management

Insulin therapy plays a vital role in diabetes management, especially for individuals with type 1 diabetes, who require exogenous insulin to survive. Additionally, for individuals with type 2 diabetes, insulin therapy may be introduced when other treatment modalities, such as oral medications, are insufficient in achieving glycemic targets. By effectively regulating blood glucose levels, insulin therapy helps individuals gain better control over their diabetes and reduces the need for hospitalizations related to diabetes complications.

It is important to note that the success of insulin therapy depends on various factors, including individual adherence to treatment, proper insulin administration techniques, regular monitoring of blood glucose levels, and ongoing communication with healthcare providers. Diabetes management is a dynamic process, and adjustments to insulin therapy may be necessary over time to maintain optimal glycemic control.

Overall, insulin therapy has demonstrated significant positive outcomes in terms of glycemic control, prevention of complications, improved quality of life, and effective diabetes management. However, it is essential for individuals to work closely with their healthcare providers to optimize insulin therapy and ensure the best possible results for their specific diabetes condition.

Discussion

Insulin therapy plays a critical role in the management of diabetes, and its discussion encompasses various aspects related to its benefits, challenges, and future directions. Here is a discussion on insulin therapy:

Benefits of insulin therapy

Insulin therapy offers several benefits in the management of diabetes:

Glycemic control

Insulin therapy allows for precise control of blood glucose levels, helping to maintain target ranges and prevent complications associated with hyperglycemia. It provides the necessary hormone that enables glucose uptake into cells, promoting normal cellular metabolism.

Flexibility

Insulin therapy offers flexibility in treatment regimens, allowing healthcare providers to tailor insulin dosages and timing to meet individual needs. This flexibility enables individuals to adjust their insulin doses based on factors such as meal size, carbohydrate content, physical activity, and illness. Long-term complication prevention Consistent glycemic control with insulin therapy has been shown to reduce the risk of long-term complications, such as cardiovascular disease, kidney disease, neuropathy, and retinopathy. By maintaining stable blood glucose levels, insulin therapy mitigates the damage caused by sustained hyperglycemia.

Improved quality of life

Insulin therapy helps alleviate symptoms associated with high blood sugar levels, such as excessive thirst, frequent urination, fatigue, and blurred vision. By controlling blood glucose, insulin therapy enhances overall wellbeing, allowing individuals to engage in daily activities without disruption.

Challenges and considerations

Despite its benefits, insulin therapy poses some challenges and considerations:

Hypoglycemia

The risk of hypoglycemia, or low blood sugar, is a significant concern with insulin therapy. Hypoglycemia can lead to symptoms ranging from mild discomfort to severe impairment and requires careful monitoring and management.

Weight gain

Some individuals may experience weight gain with insulin therapy, primarily due to improved glycemic control and enhanced glucose uptake into cells. Weight management strategies and close monitoring of dietary intake may be necessary to address this challenge.

Injection-related Issues

Subcutaneous injections can cause pain, bruising, or lipohypertrophy (thickened fatty tissue at injection sites) over time. Proper injection techniques, regular rotation of injection sites, and consultation with healthcare providers can help minimize these issues.

Psychological impact

Insulin therapy may have psychological implications for individuals, particularly those with needle phobia or fears associated with injections. Diabetes education, support from healthcare providers, and psychological support can help address these concerns.

Emerging trends and future directions

Insulin therapy continues to evolve with advancements in technology and research. Some emerging trends and future directions include:

Closed-loop systems

Closed-loop or automated insulin delivery systems, also known as artificial pancreas systems, combine continuous glucose monitoring (CGM) and insulin pump technology. These systems aim to provide automated and personalized insulin delivery based on real-time glucose levels, reducing the burden of constant self-management.

Adjunctive therapies

Research is ongoing to explore the use of adjunctive therapies, such as oral medications, GLP-1 receptor agonists, and SGLT-2 inhibitors, in combination with insulin therapy. These therapies aim to improve glycemic control, reduce insulin doses, and address specific aspects of diabetes management.

Improved insulin formulations

Continuous efforts are being made to develop new insulin formulations, including ultra-rapid-acting insulins, long-acting insulins with extended durations of action, and insulin formulations with improved stability and pharmacokinetic profiles. These advancements aim to enhance insulin efficacy, convenience, and patient satisfaction.

Conclusion

Insulin therapy is a vital component in the management of diabetes. It offers numerous benefits, including effective glycemic control, prevention of long-term complications, improved quality of life, and flexibility in treatment regimens. Insulin therapy enables individuals with diabetes to maintain stable blood glucose levels, reducing the risk of acute and chronic complications associated with the disease. However, insulin therapy also poses challenges, such as the risk of hypoglycemia and weight gain, as well as psychological considerations. Despite these challenges, ongoing advancements in technology and research continue to shape the future of insulin therapy. Emerging trends, such as closed-loop systems and adjunctive therapies, aim to enhance glycemic control, reduce treatment burden, and individualize therapy further. Additionally, the development of improved insulin formulations offers the potential for more precise and convenient insulin administration. Personalized medicine is becoming increasingly important in insulin therapy, with healthcare providers tailoring treatment regimens to individual needs and preferences. Regular monitoring, education, and support are crucial for successful insulin therapy outcomes. In conclusion, insulin therapy has transformed the management of diabetes and has significantly improved the lives of individuals with the disease. By enabling effective glycemic control and minimizing the risk of complications, insulin therapy plays a vital role in achieving better health outcomes for people living with diabetes.

References

1. Makam AN, Nguyen OK. An Evidence-Based Medicine Approach to Antihyperglycemic Therapy in Diabetes Mellitus to Overcome Overtreatment. Circulation. 135, 180-195 (2017).

Indexed at, Google Scholar, Crossref

2. Davis N, Forbes B, Wylie-Rosett J et al. Nutritional strategies in type 2 diabetes mellitus. Mt Sinai J Med. 76, 257-268 (2009).

Indexed at, Google Scholar, Crossref

3. Feinman RD, Pogozelski WK, Astrup A et al. Dietary carbohydrate restriction as the first approach in diabetes management: critical review and evidence base. Nutrition. 31, 1-13 (2015).

Indexed at, Google Scholar, Crossref

4. Abate N, Chandalia M. Ethnicity and type 2 diabetes: focus on Asian Indians. JDC. 15, 320-327 (2001).

Indexed at, Google Scholar, Crossref

5. Dixon JB, le Roux CW, Rubino F, et al. Bariatric surgery for type 2 diabetes. Lancet. 379, 2300-2311 (2012).

Google Scholar, Crossref

6. Schulman AP, Del Genio F, Sinha N et al. Metabolic surgery for treatment of type 2 diabetes mellitus. Endocrine Practice. 15, 624-631.

Indexed at, Google Scholar, Crossref

7. Currie Craig J, Peters John R, Tynan Aodán et al. Survival as a function of HbA1c in people with type 2 diabetes: a retrospective cohort study. The Lancet. 375, 481-489 (2010).

Indexed at, Google Scholar, Crossref

8. Heller, Simon R. A Summary of the Advance Trial. Diabetes Care. 32, 357-361 (2009).

Indexed at, Google Scholar, Crossref

9. Gerstein HC, Miller ME, Byington RP et al. Effects of Intensive Glucose Lowering in Type 2 Diabetes. NEJM. 358, 2545-2559.

Indexed at, Google Scholar, Crossref

10. Ritz E, Zeng XX, Rych I et al. Clinical manifestation and natural history of diabetic nephropathy. Cont rib Nephrol. 170, 132-155 (2011).

Indexed at, Google Scholar, Crossref

11. Doshi SM, Friedman AN. Diagnosis and management of type 2diabetic kidney disease. Clin J A Soc Nephrol.12, 136-156 (2017).

Google Scholar, Crossref

12. Pugliese G. Updating the natural history of diabetic nephropathy. Act Diabetol. 51, 905-943(2015).

Indexed at, Google Scholar, Crossref

13. Partridge L, Deelen J, Slagboom PE et al. Facing up to the global challenges of ageing. Nature. 561, 45-56 (2018).

Indexed at, Google Scholar, Crossref

14. Coman V, Vodnar DC. Gut microbiota and old age: Modulating factors and interventions for healthy longevity. Experimental Gerontology. 141, 111095 (2020).

Indexed at, Google Scholar, Crossref

15. DeJong EN, Surette MG, Bowdish DM et al. The Gut Microbiota and Unhealthy Aging: Disentangling Cause from Consequence.Cell Host Microbe. 28, 180-189 (2020).

Indexed at, Google Scholar, Crossref