Self-reported changes in capillary glucose and insulin requirements during the menstrual cycle

Emerging Perspectives on the Impact of Diabetes Mellitus and Anti-Diabetic Drugs on Premenstrual Syndrome. A Narrative Review

Diabetes mellitus (DM) and premenstrual syndrome (PMS) are global health challenges. Both disorders are often linked to a range of physical and psychological symptoms that significantly impact the quality of life of many women. Yet, the exact relation between DM and PMS is not clear, and the management of both conditions poses a considerable challenge. In this review, we aimed to investigate the interplay between DM, anti-diabetic drugs, and the different theories and symptoms of PMS. Female sex hormones are implicated in the pathophysiology of PMS and can also impair blood glucose control. In addition, patients with diabetes face a higher susceptibility to anxiety and depression disorders, with a significant number of patients experiencing symptoms such as fatigue and difficulty concentrating, which are reported in patients with PMS as well. Complications related to diabetic medications, such as hypoglycemia (with sulfonylurea) and fluid retention (with thiazolidinediones) may also mediate PMS-like symptoms. DM can, in addition, disturb the normal gut microbiota (GM), with a consequent loss of beneficial GM metabolites that guard against PMS, particularly the short-chain fatty acids and serotonin. Among the several available anti-diabetic drugs, those (1) with an anti-inflammatory potential, (2) that can preserve the beneficial GM, and (3) possessing a lower risk for hypoglycemia, might have a favorable outcome in PMS women. Yet, well-designed clinical trials are needed to investigate the anti-diabetic drug(s) of choice for patients with diabetes and PMS.

Variability of Glycemic Outcomes and Insulin Requirements Throughout the Menstrual Cycle: A Qualitative Study on Women With Type 1 Diabetes Using an Open-Source Automated Insulin Delivery System

BACKGROUND

The impact of hormone dynamics throughout the menstrual cycle on insulin sensitivity represents a currently under-researched area. Despite therapeutic and technological advances, self-managing insulin therapy remains challenging for women with type 1 diabetes (T1D).

METHODS

To investigate perceived changes in glycemic levels and insulin requirements throughout the menstrual cycle and different phases of life, we performed semi-structured interviews with 12 women with T1D who are using personalized open-source automated insulin delivery (AID) systems. Transcripts were analyzed using thematic analysis with an inductive, hypothesis-generating approach.

RESULTS

Participants reported significant differences between the follicular phase, ovulation, and luteal phase of the menstrual cycle and also during puberty, pregnancy, and menopause. All participants reported increased comfort and safety since using AID, but were still required to manually adjust their therapy according to their cycle. A lack of information and awareness and limited guidance by health care providers were frequently mentioned. Although individual adjustment strategies exist, achieving optimum outcomes was still perceived as challenging.

CONCLUSIONS

This study highlights that scientific evidence, therapeutic options, and professional guidance on female health-related aspects in T1D are insufficient to date. Further efforts are required to better inform people with T1D, as well as for health care professionals, researchers, medical device manufacturers, and regulatory bodies to better address female health needs in therapeutic advances.

Menstrual Cycle, Glucose Control and Insulin Sensitivity in Type 1 Diabetes: A Systematic Review

The correlation between the menstrual cycle and glucose control in type 1 diabetes has been the focus of several studies since the 1920s, but a few critical aspects made it particularly challenging to reach conclusive evidence. The aim of this systematic review is to reveal more solid information about the impact of the menstrual cycle on glycaemic outcomes and insulin sensitivity in type 1 diabetes and highlight the less researched areas. The literature was searched by two authors independently using PubMed/MEDLINE, Embase and Scopus (last search on 2 November 2022). The retrieved data did not allow us to perform a meta-analysis. We included 14 studies published between 1990 and 2022, with sample sizes from 4 to 124 patients. We found a wide heterogeneity in the definition of the menstrual cycle phases, glucose metrics, techniques for determining insulin sensitivity, hormonal assessment and other interfering factors considered, with an overall high risk of bias. There is no conclusive evidence, and published data do not allow us to achieve quantitative results. In a subset of patients, a possible worsening of insulin sensitivity and hyperglycaemia in the luteal phase could be observed. From the clinical standpoint, a cautious strategy based on patient-specific patterns can be considered until new, solid evidence is obtained.

Type 1 Diabetes and the Menstrual Cycle: Where/How Does Exercise Fit in?

Regular exercise is associated with substantial health benefits for individuals with type 1 diabetes (T1D). However, the fear of hypoglycemia (low blood glucose) due to activity-induced declines in blood glucose levels acts as a major barrier to partaking in exercise in this population. For females with T1D, hormonal fluctuations during the menstrual cycle and their effects on blood glucose levels can act as an additional barrier. The impact that these cyclic changes may have on blood glucose and insulin needs and the consequent risk of hypoglycemia during or after exercise are still unknown in this population. Therefore, in this narrative review, we gathered existing knowledge about the menstrual cycle in T1D and the effects of different cyclic phases on substrate metabolism and glucose response to exercise in females with T1D to increase knowledge and understanding around exercise in this underrepresented population. This increased knowledge in such an understudied area can help to better inform exercise guidelines for females with T1D. It can also play an important role in eliminating a significant barrier to exercise in this population, which has the potential to increase activity, improve mental health and quality of life, and decrease the risk of diabetes-related complications.

Ambulatory Glucose Profile According to Different Phases of the Menstrual Cycle in Women Living With Type 1 Diabetes

CONTEXT

Some women living with type 1 diabetes complain of changes in glucose values according to the different phases of menstruation.

OBJECTIVE

To evaluate this variability through continuous glucose monitoring (CGM) data in type 1 diabetes patients.

DESIGN

Observational study.

SETTING

Ambulatory data, recruitment in 2 centers in the Paris region.

PATIENTS

Twenty-four women with type 1 diabetes having spontaneous menstrual cycles.

INTERVENTION

Collection of CGM data for 62 spontaneous menstrual cycles, with evaluation of five 3-day phases during each cycle: (1) early follicular (menstruations), (2) mid-follicular, (3) peri-ovulatory, (4) mid-luteal, and (5) late luteal.

MAIN OUTCOME MEASURE

Time in range (TIR, prespecified).

RESULTS

TIR decreased for each consecutive phase (61 ± 18%; 59 ± 18%; 59 ± 20%; 57 ± 18%; and 55 ± 20%, P = 0.02). The linear mixed model highlighted a decrease in TIR in the mid-luteal (P = 0.03) and late luteal (P < 0.001) phases compared with the early follicular phase. Time above range was significantly higher during the late luteal phase than the early follicular phase (P = 0.003). Time below range was significantly higher during the mid-follicular phase than in the early follicular phase.

CONCLUSION

In most of the study population, glucose levels rose linearly throughout the menstrual cycle, reaching a maximum in the late luteal phase. A sharp decrease was seen for most participants at the beginning of menstrual bleeding. This should be taken into consideration in daily care of type 1 diabetes patients to avoid hypoglycemia.

Insulin Delivery and Glucose Variability Throughout the Menstrual Cycle on Closed Loop Control for Women with Type 1 Diabetes

Objective: To analyze insulin delivery and glycemic metrics throughout the menstrual cycle for women with type 1 diabetes using closed loop control (CLC) insulin delivery. Methods: Menstruating women using a CLC system in a clinical trial were invited to record their menstrual cycles through a cycle-tracking application. Sixteen participants provided data for this secondary analysis over three or more complete cycles. Insulin delivery and continuous glucose monitoring (CGM) data were analyzed in relation to reported cycle phases. Results: Insulin delivery and CGM metrics remained consistent during cycle phases. Intraparticipant variability of CGM metrics and weight-based insulin delivery did not change through cycle phases. Conclusions: For this sample of menstruating women with type 1 diabetes using a CLC system, insulin delivery and glycemic metrics remained stable throughout menstrual cycle phases. Additional studies in this population are needed, particularly among women who report variable glycemic control during their cycles. Trial Registration: NCT03591354.

Substantial Intra-Individual Variability in Post-Prandial Time to Peak in Controlled and Free-Living Conditions in Children with Type 1 Diabetes

The optimal time to bolus insulin for meals is challenging for children and adolescents with type 1 diabetes (T1D). Current guidelines to control glucose excursions do not account for individual differences in glycaemic responses to meals. This study aimed to examine the within- and between-person variability in time to peak (TTP) glycaemic responses after consuming meals under controlled and free-living conditions. Participants aged 8–15 years with T1D ≥ 1 year and using a continuous glucose monitor (CGM) were recruited. Participants consumed a standardised breakfast for six controlled days and maintained their usual daily routine for 14 free-living days. CGM traces were collected after eating. Linear mixed models were used to identify within- and between-person variability in the TTP after each of the controlled breakfasts, free-living breakfasts (FLB), and free-living dinners (FLD) conditions. Thirty participants completed the study (16 females; mean age and standard deviation (SD) 10.5 (1.9)). The TTP variability was greater within a person than the variability between people for all three meal types (between-person vs. within-person SD; controlled breakfast 18.5 vs. 38.9 min; FLB 14.1 vs. 49.6 min; FLD 5.7 vs. 64.5 min). For the first time, the study showed that within-person variability in TTP glycaemic responses is even greater than between-person variability.

The competitive athlete with type 1 diabetes

Regular exercise is important for health, fitness and longevity in people living with type 1 diabetes, and many individuals seek to train and compete while living with the condition. Muscle, liver and glycogen metabolism can be normal in athletes with diabetes with good overall glucose management, and exercise performance can be facilitated by modifications to insulin dose and nutrition. However, maintaining normal glucose levels during training, travel and competition can be a major challenge for athletes living with type 1 diabetes. Some athletes have low-to-moderate levels of carbohydrate intake during training and rest days but tend to benefit, from both a glucose and performance perspective, from high rates of carbohydrate feeding during long-distance events. This review highlights the unique metabolic responses to various types of exercise in athletes living with type 1 diabetes. Graphical abstract.

Gynaecology problems in puberty

With the onset of puberty a range of problems may be encountered by the young girl. Some of these include a range of gynaecological issues relating to delayed onset of puberty, delayed menarche, atypical pubertal changes and the identification of anomalies of the genital tract. The distinction between physiological events and pathological problems is important to avoid unnecessary distress and anxiety. The onset of cyclic hormonal changes also provokes a number of "non-gynaecological" problems - where the link to cyclic hormonal events is often overlooked and an important opportunity to potentially intervene and assist is missed. From a global perspective there are a range of problems that are particularly encountered with the onset of puberty including the risks of sexual violence, which in the setting of having achieved the age of reproductive potential result in unplanned pregnancies, unsafe abortions and adolescent pregnancy all of which pose life threatening risks. Sex education in its broadest sense is important for all young people. Access to contraception for adolescents is vital, such that clinicians across all streams of health care who are involved in the care of young people should take the opportunity to educate and provide this care.

Fluctuations of Hyperglycemia and Insulin Sensitivity Are Linked to Menstrual Cycle Phases in Women With T1D

BACKGROUND

Factors influencing glycemic variability in type 1 diabetes (T1D) may play a significant role in the refinement of closed loop insulin administration. Phase of menstrual cycle is one such factor that has been inadequately investigated. We propose that unique individual patterns can be constructed and used as parameters of closed loop systems.

METHOD

Women with T1D on continuous subcutaneous insulin infusion and continuous glucose monitoring were studied for 3 consecutive menstrual cycles. Ovulation prediction kits and labs were used to confirm phase of menstrual cycle. Glycemic risks were assessed using the low- and high blood glucose indices (LBGI and HBGI). Insulin sensitivity (SI) was estimated using a Kalman filtering method from meal and insulin data. Overall change significance for glycemic risks was assessed by repeated measures ANOVA, with specific phases emphasized using contrasts.

RESULTS

Ovulation was confirmed in 33/36 cycles studied in 12 subjects (age = 33.1 ± 7.0 years, BMI = 25.7 ± 2.9 kg/m(2), A1c = 6.8 ± 0.7%). Risk for hyperglycemia changed significantly during the cycle (P = .023), with HBGI increasing until early luteal phase and returning to initial levels thereafter. LBGI was steady in the follicular phase, decreasing thereafter but not significantly. SI was depressed during the luteal phase when compared to the early follicular phase (P ≤ .05). Total daily insulin, carbohydrates, or calories did not show any significant fluctuations.

CONCLUSIONS

Women with T1D have glycemic variability changes that are specific to the individual and are linked to phase of cycle. An increased risk of hyperglycemia was observed during periovulation and early luteal phases compared to the early follicular phase; these changes appear to be associated with decreased insulin sensitivity during the luteal phase.

Female reproduction and type 1 diabetes: from mechanisms to clinical findings

BACKGROUND

The functional reproductive alterations seen in women with type 1 diabetes (T1D) have changed as therapy has improved. Historically, patients with T1D and insufficient metabolic control exhibited a high prevalence of amenorrhea, hypogonadism and infertility. This paper reviews the impact of diabetes on the reproductive axis of female T1D patients treated with modern insulin therapy, with special attention to the mechanisms by which diabetes disrupts hypothalamic-pituitary-ovarian function, as documented mainly by animal model studies.

METHODS

A comprehensive MEDLINE search of articles published from 1966 to 2012 was performed. Animal model studies on experimental diabetes and human studies on T1D were examined and cross-referenced with terms that referred to different aspects of the gonadotropic axis, gonadotrophins and gonadal steroids.

RESULTS

Recent studies have shown that women with T1D still display delayed puberty and menarche, menstrual irregularities (especially oligomenorrhoea), mild hyperandrogenism, polycystic ovarian syndrome, fewer live born children and possibly earlier menopause. Animal models have helped us to decipher the underlying basis of these conditions and have highlighted the variable contributions of defective leptin, insulin and kisspeptin signalling to the mechanisms of perturbed reproduction in T1D.

CONCLUSIONS

Despite improvements in insulin therapy, T1D patients still suffer many reproductive problems that warrant specific diagnoses and therapeutic management. Similar to other states of metabolic stress, T1D represents a challenge to the correct functioning of the reproductive axis.

Menstrual cycle effects on insulin sensitivity in women with type 1 diabetes: a pilot study

BACKGROUND

Many women complain of difficulty maintaining euglycemia during the luteal phase of the menstrual cycle. This pilot study's objective was to evaluate possible differences in insulin sensitivity between follicular and luteal phases in women with type 1 diabetes.

METHODS

Women using insulin infusion pumps (n = 5, mean age 29.2 +/- 10.9 years, mean body mass index 24 +/- 1.8 kg/m(2)) underwent frequently sampled intravenous glucose tolerance tests during each cycle phase. Insulin sensitivity and glucose effectiveness were determined by Minimal Model analysis.

RESULTS

Non-insulin-mediated glucose disposal increased during the luteal phase (0.009 +/- 0.004 min(1)) versus the follicular phase (0.005 +/- 0.003 min(1)) (P < 0.05). Although no significant differences were found in mean insulin sensitivity between follicular (0.76 +/- 0.27 x 10(4)/min(1) /microU/mL) and luteal phase (0.58 +/- 0.26 x 10(4)/min(1) /microU/ mL), three of the five subjects had a decline in insulin sensitivity.

CONCLUSIONS

Elevated blood glucose during the luteal phase may increase insulin-independent glucose disposal. Some individuals appear more responsive to menstrual cycle effects on insulin sensitivity. Women should be encouraged to use available self-monitoring technology to identify possible cyclical variations in blood glucose that might require clinician review and insulin dosage adjustments.

The association of increased total glycosylated hemoglobin levels with delayed age at menarche in young women with type 1 diabetes

CONTEXT

Delayed menarche is associated with subsequent reproductive and skeletal complications. Previous research has found delayed growth and pubertal maturation with type 1 diabetes and poor glycemic control. The effect of diabetes management on menarche is important to clarify, because tighter control might prevent these complications.

OBJECTIVE

The objective of this study was to investigate age at menarche in young women with type 1 diabetes and examine the effect of diabetes management [e.g. total glycosylated hemoglobin (GHb) level, number of blood glucose checks, insulin therapy intensity, and insulin dose] on age at menarche in those diagnosed before menarche.

DESIGN

The Wisconsin Diabetes Registry Project is a follow-up study of a type 1 diabetes population-based incident cohort initially enrolled between 1987 and 1992.

SETTING

This study was performed in 28 counties in south-central Wisconsin.

PATIENTS OR OTHER PARTICIPANTS

The study participants were recruited through referrals, self-report, and hospital/clinic ascertainment. Individuals with newly diagnosed type 1 diabetes, less than 30 yr old, were invited to participate. Of 288 young women enrolled, 188 reported menarche by 2002; 105 were diagnosed before menarche.

INTERVENTIONS

There were no interventions.

MAIN OUTCOME MEASURE

The main outcome measure was age at menarche.

RESULTS

Mean age at menarche was 12.78 yr, compared with 12.54 yr in the United States (P = 0.01). Ages at menarche and diagnosis were not associated. For those diagnosed before menarche, age at menarche was delayed 1.3 months with each 1% increase in mean total GHb level in the 3 yr before menarche.

CONCLUSIONS

Age at menarche was moderately delayed in young women with type 1 diabetes. Delayed menarche could potentially be minimized with improved GHb levels.

Cyclic changes in glycemia assessed by continuous glucose monitoring system during multiple complete menstrual cycles in women with type 1 diabetes

Many women with diabetes notice changes in glucose control perimenstrually. To describe the pattern of changes in glucose control throughout the complete menstrual cycle, and the reproducibility of these changes, we performed a pilot study evaluating glycemic profiles continuously for three cycles in four women with type 1 diabetes. All participants had hemoglobin A1c <7.5% and regular menstrual periods off oral contraceptives. They used Medtronic MiniMed (Northridge, CA) Continuous Glucose Monitoring System (CGMS) devices continuously for three complete menstrual cycles, checked capillary glucose measurements six times daily, changed their own sensors every 3 days, and were seen seven times per menstrual cycle to download data and draw blood. Prolonged monitoring was safely carried out over three consecutive menstrual cycles. We observed two different patterns of glycemic control in relation to the menstrual cycle in these women. The first pattern, seen in two women, was characterized by increased frequency of hyperglycemia in the luteal phase. One of these women also had a hyperglycemic peak in the follicular phase. In the other two women, no characteristic cycle-related pattern was noted. The glucose profiles appeared reproducible between cycles in all women, but varied between women. Thus the menstrual cycle has a reproducible effect on glucose control in a subset of women with type 1 diabetes. Prolonged use of continuous glucose monitoring was safe in the subjects studied, and is the first method clinically available to monitor glucose control over prolonged periods in individuals with diabetes.

Insulin sensitivity and premenstrual syndrome

Maintaining normal blood glucose levels is a constant challenge for women with diabetes. Anecdotal reports reveal that many women question if menstrual cycle phases may affect their blood glucose levels. However, results from studies investigating the effect of the menstrual cycle on insulin sensitivity in diabetic women have been conflicting. One variable that may account for the conflicting results is the presence or absence of premenstrual syndrome (PMS), which may exacerbate menstrual cycle-related effects on insulin sensitivity. Treatment of PMS with serotonin reuptake inhibitors may alleviate the symptoms of PMS, as well as improve insulin sensitivity and help regulate blood glucose levels.

HRT in women with diabetes--review of the effects on glucose and lipid metabolism

Hormone replacement therapy (HRT) is prescribed less frequently to women with diabetes. In this article, we review the effects of HRT on glucose metabolism and plasma lipids in women with type 2 diabetes. Current evidence is reassuring about the effects of HRT in women with diabetes, although as in all women, HRT should be prescribed on an individual basis with appropriate consideration given to advantages and disadvantages of therapy.

Dose-dependent action of glucose on memory processes in women: effect on serial position and recall priority

Previous research has shown that glucose can enhance memory in animals and humans. In humans, the facilitative effect of glucose is best observed with declarative memory tasks in older subjects. While the memory-enhancing action of glucose is well established, the underlying physiological mechanisms and the specific aspects of memory that are modulated by glucose in humans are not well understood. The present study sought to examine the effects of glucose on memory in young women using a memory paradigm sensitive to specific encoding and retrieval strategies. The glucose dose was adjusted for the weight of each participant in order to generate a dose response curve covering most doses used in previous studies. The results showed that 300 mg/kg glucose enhanced the primacy effect as defined by the recall of the first five items of the lists. However, none of the doses of glucose produced changes in the recall priority given to primacy items. The effect of glucose appears to be localized on the recall primacy effect, suggesting that glucose acts on precise memory operations. This improvement, however, is independent of the order in which subjects recalled the words. Cholinergic drugs have been shown to alter the recall of the primacy part of word lists and this observation is consistent with the hypothesis that glucose acts on memory through an interaction with brain cholinergic systems.

A population-based study of bone mineral density in women with longstanding type 1 (insulin dependent) diabetes

This study aimed to explore multiple determinants of BMD (bone mineral density) in 99 women with long-standing type 1 diabetes, recruited from a population based register of insulin users. BMD was measured using DEXA (dual energy X-ray absorptiometry) at the femoral neck and lumbar spine, age adjusted Z scores were calculated and results compared to those of healthy volunteers. The median age of diabetic subjects was 42 years and the median duration of diabetes was 27 years. BMD was positively associated with body mass index and height at both the lumbar spine and femoral neck. There was a positive association with oral contraceptive pill use and lumbar spine BMD, and peripheral vascular disease was negatively associated with femoral neck BMD. No correlation was seen with either age or duration of diabetes and absolute BMD values. Mean Z score at the femoral neck was -0.12 (95% confidence interval -0.37 to +0.12). At the lumbar spine, the corresponding value was -0.21 (-0.44 to +0.02). Pre- and post-menopausal values for the diabetic subjects and healthy volunteers were found to be similar. In summary, axial BMD values in subjects with long-standing diabetes were similar to those observed in healthy non diabetic populations.