the international diabetes federation estimated the global prevalence of diabetes to be 151 million in 2000   and 285 million in 2010 . this prevalence is expected to rise to 552 million by 2030 . in korea , after a rapid increment of the prevalence of diabetes during the last 30 years , the prevalence of diabetes in adults aged 30 years reached about 9% to 10% and remained stable between 2000 and 2010 . a recent korea national health and nutritional examination survey ( knhanes ) 2011 to 2014 showed that the prevalence of diabetes in adults aged 30 years increased to 10% to 11% . during that period , along with the trend of an increasing number of elderly people in korea , the number of elderly patients with type 2 diabetes mellitus ( t2 dm ) increased significantly . in addition , the gender disparity in the trend of the prevalence of diabetes and obesity was apparent in the 2000s . in this review , we summarized the recent trends in the prevalence of diabetes in korea , and the risk factors associated with those trends will be discussed . the prevalence of diabetes in korean adults aged 30 years remained stable at approximately 9% to 10% between 2000 and 2010 . the korean centers for disease control and prevention reported that it increased to 10% to 11% between 2011 and 2014 . if cases of diabetes mellitus ( dm ) were defined as subjects who were users of antidiabetic medication , including insulin , at the point of the survey or had 8-hour fasting plasma glucose levels 126 mg / dl , the age - standardized prevalence of diabetes using the korean population in the year 2010 was 10.0% to 10.8% in adults aged 30 years during 2001 to 2012 , which increased to 12.5% in 2013 and 11.6% in 2014 ( fig . age - standardized prevalence in 2013 and 2014 was 13.7% and 13.1% respectively ; in women , that was 11.5% and 10.3% , respectively ( fig . the age - standardized prevalence in subjects 30 to 59 years old did not change much between 2005 and 2014 : 8.3% to 10.2% in men and 4.3% to 5.9% in women ( fig . by contrast , the elderly population aged 60 years showed an increasing trend of diabetes prevalence from 19.0% in 2001 to 21.4% in 2010 and to 24.7% in 2014 ( fig . since 2011 , all adult participants in the knhanes had their glycosylated hemoglobin ( hba1c ) level measured following the guidelines of the korean diabetes association , which adopted an hba1c 6.5% as a diagnostic criterion for dm since 2011 . considering that in the previous knhanes , only participants who had a medical history of diabetes measured their hba1c level , a trend in the prevalence of diabetes estimated from the knhanes should be interpreted with caution . after adopting an hba1c 6.5% as one of the diagnostic criteria of diabetes , 2 ) as previously reported ; the age - standardized prevalence of diabetes in adults aged 30 years reached 13.2% , 12.3% , 15.6% , and 13.8% in 2011 , 2012 , 2013 , and 2014 , respectively ( fig . nationwide claim data showed that the peak incidence of t2 dm between 2008 and 2010 was observed at 60 to 79 years of age ( i.e. , 23 to 25/1,000 person - year [ py ] ) both in men and women ( fig . the incidence of diabetes in individuals 50 to 59 years old and 80 to 89 years old was next ( 18/1,000 py ) . in the case of women , the incidence of diabetes in individuals 80 to 89 years of age was next ( 17/1,000 py ) . women aged 50 to 59 years old showed a relatively lower incidence of diabetes than men of the same age ( 13/1,000 py vs. 19/1,000 py ) . korea is one of the most rapidly aging countries ; the proportion of the elderly population aged 65 years reached 11.0% in 2010 and is expected to be 22% in 2020 . the increasing size of the elderly population might result in the nationwide increasing prevalence of diabetes . considering that the increasing prevalence of diabetes may also increase the economic burden , a public strategy targeting elderly people for diabetes prevention is urgent . in the case of the younger population , a nationwide health survey showed a relatively stable prevalence of diabetes , especially in women . these results corresponded with the nationwide survey in japan   but were not observed in china . however , considering that only 50% to 60% of young diabetic patients aged 30 to 40 years have insight to have diabetes in korea , and undiagnosed diabetic patients showed a significantly higher risk of cardiovascular disease compared to diagnosed diabetic patients , a public heath strategy targeting the younger population for diabetes screening might be needed . in korea , the prevalence of obesity and abdominal obesity in the general population has increased from 2005 to 2007 ; it has remained steady since then . however , in the cases of young women , body mass index ( bmi ) and waist circumference have significantly decreased during the 2000s in the general population . by contrast , in the cases of women with diabetes of the same age , the prevalence of abdominal obesity increased from 66.3% to 72.9% during the same period . along with this trend , abdominal obesity is the single most important independent risk factor for diabetes in young korean women . it was associated with more than four times a higher risk of diabetes in 2010 even after an adjustment for age , dyslipidemia , family history , and exercise . the fact that abdominal obesity is the most important risk factor of diabetes in women was in agreement with a large cohort study conducted in the united states on young women during 16 years of follow - up . attributing the power of obesity or abdominal obesity for developing diabetes was more prominent at a young age compared to the elderly population in korean women , as well as in japanese women . in terms of men , there might be a difference in the contribution of obesity in the development of diabetes compared to women . however , there has not been much change in the prevalence of diabetes in young korean men . furthermore , in them , the association between obesity and diabetes has been attenuated . in the early 2000s , the prevalence of abdominal obesity in subjects with diabetes was about two times higher than that in nondiabetic subjects ; however , there was no difference in the prevalence of abdominal obesity between subjects with and without diabetes in 2010 . instead , the association between a family history of diabetes and dm in these subjects was much stronger in the late 2000s . the main pathogenic mechanism in developing t2 dm in obesity or aging is insulin resistance ; however , more than 70% of obese or elderly people are free of diabetes . recently , a 10-year follow - up cohort study showed that insulin sensitivity was significantly decreased with aging , regardless of the glucose tolerance state at the follow - up . however , compared with participants who remained normal glucose tolerance ( ngt ) , those who progressed to diabetes had a lower -cell function , which agreed with previous reports in japan   and a multiethnic population . they have suggested that impaired -cell function might be the determining factor whether or not t2 dm develops or the condition of insulin resistance increased . the main determinants of -cell function in t2 dm is genetic factor associated with the insulin secretion capacity and the proliferation and regeneration of -cells . a long - term cohort study in korea also confirmed that a genetic variant near the glucokinase gene was significantly associated with the progression to diabetes . in terms of age of onset , -cell dysfunction might be more important in people with early - onset diabetes compared to elderly - onset diabetic patients , which was also reproduced in korea . among people with recent - onset diabetes from the knhanes , defined as those who have diabetes for < 5 years , there was an inverse correlation between age and the homeostasis model assessment of -cell function ( fig . , young diabetic patients were more influenced by a family history of diabetes compared to elderly patients , which was in agreement with caucasians . in young men , a family history of diabetes was associated with more than six times a higher risk of diabetes . in the case of women of the same age , however , the presence of obesity but not family history was the most important determinant of diabetes status . a decrease in the insulin sensitivity with the aging is well known , even in individuals who remained as ngt at 10 years , which can be partially explained by decreased muscle mass ( i.e. , sarcopenia , along with increased fat mass ) . the knhanes 2008 to 2010 showed that for elderly - onset diabetic patients , insulin resistance was more prominent compared to middle - age - onset patients at the time of diagnosis . although insulin resistance was higher in the elderly - onset diabetic patients compared to the middle - age - onset patients , the bmi , waist circumference , and body fat mass of the elderly - onset subjects were not different across the age group , which was in agreement with the chinese population . in a cross - sectional study comparing caucasian and chinese patients with recent - onset diabetes ( duration < 2 years ) , a negative correlation between the age at diagnosis and bmi or insulin resistance was only observed in caucasians . in chinese diabetic patients , there was no relationship between age at diagnosis and bmi , insulin resistance , or triglyceride level . instead , a korean nationwide survey showed that elderly - onset diabetic patients had significantly lower skeletal muscle mass and higher prevalence of sarcopenia compared with the middle - age - onset group . comparing the elderly - onset diabetic patients with the age - matched ngt subjects ( although there was no difference in the sarcopenia class i prevalence ) ( milder form of sarcopenia ; 1 to 2 standard deviations below the gender - specific mean for healthy young adults ) , the advanced stage of sarcopenia ( > 2 standard deviations below the gender - specific mean for healthy young adults ; classified as class ii ) was found about three times more frequently in those with recent - onset diabetes compared with nondiabetic subjects ( fig . 5 ) . low socioeconomic status ( ses ) is a well - documented risk factor of diabetes in developed countries . korea is one of the most rapidly developing countries in the world ; low ses has been an emerging risk factor for dm in recent years . both low income status and low education level were significantly associated with the risk of diabetes in the knhanes 2008 to 2012 even after an adjustment for other risk factors ( i.e. , obesity and dyslipidemia ) , which was not observed in 2001 or 2005 . in other asian countries , such as india and china , the same tendency was also observed . in addition , the association between ses and diabetes was prominent in people less than 65 years old . poorer and less educated people have fewer opportunities for primary prevention , early diagnosis , and appropriate management ; however , these disadvantages can be overcome . the reduction of obesity in populations with a lower ses has proven to be successful for preventing diabetes in india , which might be another possible strategy for reducing health inequality according to ses . in korea , the prevalence of obesity and abdominal obesity in the general population has increased from 2005 to 2007 ; it has remained steady since then . however , in the cases of young women , body mass index ( bmi ) and waist circumference have significantly decreased during the 2000s in the general population . by contrast , in the cases of women with diabetes of the same age , the prevalence of abdominal obesity increased from 66.3% to 72.9% during the same period . along with this trend , abdominal obesity is the single most important independent risk factor for diabetes in young korean women . it was associated with more than four times a higher risk of diabetes in 2010 even after an adjustment for age , dyslipidemia , family history , and exercise . the fact that abdominal obesity is the most important risk factor of diabetes in women was in agreement with a large cohort study conducted in the united states on young women during 16 years of follow - up . attributing the power of obesity or abdominal obesity for developing diabetes was more prominent at a young age compared to the elderly population in korean women , as well as in japanese women . in terms of men , there might be a difference in the contribution of obesity in the development of diabetes compared to women . however , there has not been much change in the prevalence of diabetes in young korean men . furthermore , in them , the association between obesity and diabetes has been attenuated . in the early 2000s , the prevalence of abdominal obesity in subjects with diabetes was about two times higher than that in nondiabetic subjects ; however , there was no difference in the prevalence of abdominal obesity between subjects with and without diabetes in 2010 . instead , the association between a family history of diabetes and dm in these subjects was much stronger in the late 2000s . the main pathogenic mechanism in developing t2 dm in obesity or aging is insulin resistance ; however , more than 70% of obese or elderly people are free of diabetes . recently , a 10-year follow - up cohort study showed that insulin sensitivity was significantly decreased with aging , regardless of the glucose tolerance state at the follow - up . however , compared with participants who remained normal glucose tolerance ( ngt ) , those who progressed to diabetes had a lower -cell function , which agreed with previous reports in japan   and a multiethnic population . they have suggested that impaired -cell function might be the determining factor whether or not t2 dm develops or the condition of insulin resistance increased . the main determinants of -cell function in t2 dm is genetic factor associated with the insulin secretion capacity and the proliferation and regeneration of -cells . a long - term cohort study in korea also confirmed that a genetic variant near the glucokinase gene was significantly associated with the progression to diabetes . in terms of age of onset , -cell dysfunction might be more important in people with early - onset diabetes compared to elderly - onset diabetic patients , which was also reproduced in korea . among people with recent - onset diabetes from the knhanes , defined as those who have diabetes for < 5 years , there was an inverse correlation between age and the homeostasis model assessment of -cell function ( fig . 4 ) . in addition , young diabetic patients were more influenced by a family history of diabetes compared to elderly patients , which was in agreement with caucasians . in young men , a family history of diabetes was associated with more than six times a higher risk of diabetes . in the case of women of the same age , however , the presence of obesity but not family history was the most important determinant of diabetes status . a decrease in the insulin sensitivity with the aging is well known , even in individuals who remained as ngt at 10 years , which can be partially explained by decreased muscle mass ( i.e. , sarcopenia , along with increased fat mass ) . the knhanes 2008 to 2010 showed that for elderly - onset diabetic patients , insulin resistance was more prominent compared to middle - age - onset patients at the time of diagnosis . although insulin resistance was higher in the elderly - onset diabetic patients compared to the middle - age - onset patients , the bmi , waist circumference , and body fat mass of the elderly - onset subjects were not different across the age group , which was in agreement with the chinese population . in a cross - sectional study comparing caucasian and chinese patients with recent - onset diabetes ( duration < 2 years ) , a negative correlation between the age at diagnosis and bmi or insulin resistance was only observed in caucasians . in chinese diabetic patients , there was no relationship between age at diagnosis and bmi , insulin resistance , or triglyceride level . instead , a korean nationwide survey showed that elderly - onset diabetic patients had significantly lower skeletal muscle mass and higher prevalence of sarcopenia compared with the middle - age - onset group . comparing the elderly - onset diabetic patients with the age - matched ngt subjects ( although there was no difference in the sarcopenia class i prevalence ) ( milder form of sarcopenia ; 1 to 2 standard deviations below the gender - specific mean for healthy young adults ) , the advanced stage of sarcopenia ( > 2 standard deviations below the gender - specific mean for healthy young adults ; classified as class ii ) was found about three times more frequently in those with recent - onset diabetes compared with nondiabetic subjects ( fig . low socioeconomic status ( ses ) is a well - documented risk factor of diabetes in developed countries . korea is one of the most rapidly developing countries in the world ; low ses has been an emerging risk factor for dm in recent years . both low income status and low education level were significantly associated with the risk of diabetes in the knhanes 2008 to 2012 even after an adjustment for other risk factors ( i.e. , obesity and dyslipidemia ) , which was not observed in 2001 or 2005 . in other asian countries , such as india and china , the same tendency was also observed . in addition , the association between ses and diabetes was prominent in people less than 65 years old . poorer and less educated people have fewer opportunities for primary prevention , early diagnosis , and appropriate management ; however , these disadvantages can be overcome . the reduction of obesity in populations with a lower ses has proven to be successful for preventing diabetes in india , which might be another possible strategy for reducing health inequality according to ses . in the 2000s , despite a steady state of the overall prevalence of diabetes , there have been changes in the gender- , age- , and ses - specific prevalence in korean adults . a nationwide survey showed that there was a difference in major determining risk factors of diabetes according to each gender and age group . considering the economic burden of diabetes and its associated comorbidities , a public health policy targeting major risk factors in each population ( i.e. , obesity in women or sarcopenia in older people ) might be more effective in preventing diabetes at the national level .
in the early 2000s , the prevalence of diabetes in adults aged 30 years in korea was about 9% to 10% , and it remained stable . 
 however , a nationwide survey showed that this prevalence increased over the past few years . 
 after age - standardization using the korean population of the year 2010 , the prevalence of diabetes in adults aged 30 years was 10.0% to 10.8% between 2001 and 2012 , which increased to 12.5% in 2013 and 11.6% in 2014 . during that period , 
 there have been changes in the gender- and age - specific prevalence of diabetes in korean adults . 
 the prevalence of diabetes in the elderly population increased significantly , while this prevalence in young adults , especially in young women , did not change significantly . 
 the contribution of each diabetic risk factor , such as obesity , -cell dysfunction , sarcopenia , and socioeconomic status , in developing diabetes has also changed during that period in each gender and age group . for young women , 
 obesity was the most important risk factor ; by contrast , for elderly diabetic patients , sarcopenia was more important than obesity as a risk factor . considering the economic burden of diabetes and its associated comorbidities , a public health policy targeting the major risk factors in each population might be more effective in preventing diabetes .